eBay Comp Checker

Paste any item description; get a conservative resale value from real sold comps.

Tested in Museprompt packDeal huntinginstructionscomp-methodconfidence-rating

by Muse Skills editors · Written for this directory

Install the "eBay Comp Checker" prompt pack. Its full source is below. Save it at
~/workspace/prompts/ebay-comp-checker.md exactly as given, with the frontmatter
(name and description) and the prompt body. Do not run it now. Then
confirm it is saved and tell me the trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

--- SOURCE ---
# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

View source

Ready to copy.

Details

Type: prompt pack
Category: Deal hunting
Version: 1.0.0
Added: 9 Sep 2026
Author: Muse Skills editorsWritten for this directory
Includes: instructionscomp-methodconfidence-rating
Source: github.com/…/ebay-comp-checker.md

Install the "eBay Comp Checker" prompt pack. Its full source is below. Save it at
~/workspace/prompts/ebay-comp-checker.md exactly as given, with the frontmatter
(name and description) and the prompt body. Do not run it now. Then
confirm it is saved and tell me the trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

--- SOURCE ---
# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

Before you install

A shared skill carries somebody else's instructions. Read the source before you install it.
Never paste an API key, password, or token into anything a skill asks for. Legitimate skills use Muse's own secure flows.
Installing copies the setup into your own environment. It gives the author nothing.

What it does

eBay Comp Checker answers one question fast: what is this thing actually worth? Paste a description: brand, model, size, condition, and it searches eBay’s sold listings for the closest matches, then sets the conservative comp at the lowest match, not the average.

It never uses active listings or asking prices, and it tells you when the data is too thin to trust. Built for the moment you’re staring at a marketplace listing wondering if the price is real.

What it includes

Sold-listing search method (sold only, never asking prices)
The lowest-of-matches comp rule
Confidence rating with a one-line reason
Thin-data behavior: say so, don’t guess

Example

Input: “LEGO Harry Potter Hogwarts Castle 71043, sealed box, slight shelf wear.”

Output:

Item: LEGO 71043 Hogwarts Castle, sealed
Sold comps: $380, $365, $372, $350, $389 (last 60 days)
Conservative comp: $350 (lowest of 5 matches)
Confidence: high, five sealed-box matches in 60 days

What this one touches

Reads public sold-listing data only. Writes nothing, buys nothing, lists nothing. Never asks for an eBay login; it uses Muse's own browsing.

Install

Copy this block and paste it into your Muse chat. Muse does the install and confirms when it's done.

Install prompt

Install the "eBay Comp Checker" prompt pack. Its full source is below. Save it at
~/workspace/prompts/ebay-comp-checker.md exactly as given, with the frontmatter
(name and description) and the prompt body. Do not run it now. Then
confirm it is saved and tell me the trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

--- SOURCE ---
# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

Install the "eBay Comp Checker" prompt pack. Its full source is below. Save it at
~/workspace/prompts/ebay-comp-checker.md exactly as given, with the frontmatter
(name and description) and the prompt body. Do not run it now. Then
confirm it is saved and tell me the trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

--- SOURCE ---
# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

Full source

This is the exact text Muse installs. Read it. That's the whole trust model.

SKILL.md

# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

# eBay Comp Checker

How to use: paste an item description with as much detail as you
have: brand, model, size or variant, condition, and anything that
affects value (edition, year, completeness). Ask for "comp this"
any time you are staring at a listing and wondering if the price
is real.

Trigger phrases: "comp this item", "find eBay comps", "price this eBay item".

## The prompt

You are pricing a used item from eBay sold data. Work in this
order:

1. Search eBay's sold and completed listings for the closest
   matches: same brand and model, same size or variant, comparable
   condition.
2. Collect the 5 most recent matching sold prices. Ignore active
   listings, asking prices, and outliers more than 2x the median.
3. Set the conservative comp to the LOWEST of the matched sold
   prices, not the average, not the median.
4. Report in this shape:
   - Item: what you matched on
   - Sold comps: the matched prices, newest first, with dates
   - Conservative comp: $X (lowest of N matches)
   - Confidence: high / medium / low, with one line on why
5. If fewer than 3 solid matches exist, say so plainly and mark
   confidence low. Never pad thin data with guesses.
6. Never invent a sold listing. If you cannot find real sold data,
   say that instead of estimating.

Rules: report only. Never contact a seller, place a bid, or suggest
a listing strategy beyond the comp itself.

Open Box Hunter
Hunts open-box, refurbished, and clearance deals on the exact product you name, and ranks them by real savings over new.
skillinstructionsworkflowprice-comparisoncondition-checklist
by Muse Skills editors · Written for this directory
ViewInstall the "Open Box Hunter" skill. Its full source is below. Create it at ~/workspace/skills/open-box-hunter/SKILL.md following skill-creator conventions (name and description frontmatter; Purpose, Workflow, Output Contract, Operating Rules sections). Then confirm it is installed and tell me the trigger phrases. --- SOURCE --- --- name: open-box-hunter description: Finds open-box, refurbished, and clearance deals on a product you name: compares retailer prices, checks condition grades, and ranks offers by real savings. Trigger phrases: "find an open-box deal on", "cheapest refurbished", "clearance price for", "open box deals", "refurbished alternative". --- # Purpose Do one narrow job: when you already know the product you want but would rather not pay full retail, find the best discounted way to buy it. The skill searches open-box listings, certified refurbished stock, and clearance markdowns across major retailers, compares the effective price (after shipping, tax, and warranty differences), and ranks offers by true savings against the current new price. It never hides what is missing: every verdict shows condition, accessories, return window, and warranty side by side, so a cheap price with a 14-day return and no charger does not win by accident. # Workflow 1. Collect the inputs: the exact product name or model number, your acceptable condition grades (open-box excellent, good, or fair; certified refurbished; store clearance), your max budget, and whether accessories and manuals must be intact. 2. Establish the baseline: find the current new price from a major retailer, not the list price, so savings are measured against what you would actually pay today. 3. Build the candidate list: check the big open-box sources (Best Buy open-box, Amazon Warehouse, manufacturer refurbished stores, manufacturer clearance pages), plus reputable general marketplaces, for the exact model. 4. For each candidate record the price, shipping cost, condition grade, what is included or missing, the return window, and the warranty status. 5. Compute true savings per offer versus the new-price baseline, then rank the offers. Flag any deal where missing accessories or a short return window erase the apparent discount. 6. Present the ranked list with links and a one-line verdict on each: worth it, borderline, or skip. Ask about budget and condition limits before starting if the user did not give them. # Output Contract - The current new price used as the baseline, with its source - A ranked list of offers: price, shipping, condition grade, included and missing items, return window, warranty - True savings per offer versus new, in dollars and percent - A one-line verdict on each offer: worth it, borderline, or skip, with the reason - A note on any candidate that could not be verified with a live listing # Operating Rules - Always compare against the live new price, not the list price, so savings are real. - Never hide missing accessories, short return windows, or warranty gaps in a verdict. Show them next to the price. - Never recommend an offer you cannot verify with a live listing; say which offers you could not check. - Never push the buyer below the minimum condition grade they set. - Never share the buyer's personal or location data in any search you run.
Auction Bid Calculator
Sets a hard bid ceiling for an auction lot after fees, tax, shipping, and your margin.
Tested in Museskillinstructionsworkflowcalculator
by Muse Skills editors · Written for this directory
ViewInstall the "Auction Bid Calculator" skill. Its full source is below. Create it at ~/workspace/skills/auction-bid-calculator/SKILL.md following skill-creator conventions (name and description frontmatter; Purpose, Workflow, Output Contract, Operating Rules sections). Then confirm it is installed and tell me the trigger phrases. --- SOURCE --- --- name: auction-bid-calculator description: Computes your maximum bid for an estate or online auction lot, accounting for buyer premium, sales tax, shipping, and your target margin. Trigger phrases: "what should I bid", "auction bid ceiling", "is this lot worth bidding on". --- # Purpose Set a hard ceiling for an auction lot before the bidding starts, so the fees and taxes do not turn a win into a loss. # Workflow 1. Read the lot details: item description, current bid, estimate, and the auction's buyer premium percentage and payment terms. 2. Read the sales tax rate for the auction location and the shipping cost if it is not local pickup. 3. Read the target: the item's conservative resale value and the margin the user wants to keep. 4. Compute the ceiling: the highest hammer price such that the hammer price plus buyer premium plus sales tax plus shipping plus any other fees stays at or below the target value after the margin. 5. Show the math line by line, then the ceiling as one bold number. 6. Optionally produce a bid plan: the opening bid and the last comfortable step below the ceiling. # Output Contract - One-line verdict: the maximum hammer price to bid, plus the all-in cost at that price. - A short math breakdown: hammer price, buyer premium, sales tax, shipping, other fees, total. - Target resale value and the dollar margin the plan protects. - If the current bid already exceeds the ceiling, say so in the first sentence and do not propose higher bids. # Operating Rules - Never guess the buyer premium, tax rate, or shipping cost; ask for each value if the user has not supplied it, and mark any assumption plainly when the user approves a default. - Never recommend bidding above the computed ceiling. - Never fabricate resale comps; use comps the user confirms or recent sold data, and state the low end of the range. - Never place bids or access an auction account; this is math and planning only.
Auction Ending Alert
Watches your saved auctions; pings before close with your max bid.
Tested in Museworkflowinstructionsworkflowschedule
by Muse Skills editors · Written for this directory
ViewSet up the "Auction Ending Alert" workflow. Its full source is below. Default schedule: every 30 minutes. Ask me to confirm or change the cadence before you create the recurring job. Once I confirm, create the job. Tell me the job name and the confirmed schedule when it is set up. --- SOURCE --- name: auction-ending-alert description: Watch a list of auctions and alert before each one closes, with the current price, your max bid, and whether the deal still clears your bar. Trigger phrases: "watch these auctions", "alert me before my auctions end", "track my bids". schedule: every 30 minutes. Confirm the cadence with the user before the first scheduled run. trigger: the scheduled time, or a manual "watch these auctions" request with links. steps: 1. Ask the user for the auction links and a max bid for each. Save the watch list. 2. Each run: check the current price, bid count, and time remaining for every watched auction. 3. Alert rules: - Ending within 2 hours: send the pre-close alert. - Price already above the user's max: mark "over your max" and stop watching it unless told otherwise. - Auction ended: report the outcome (won/lost, final price) once, then drop it from the list. 4. The pre-close alert uses the Output shape. output: - Ending soon: item, time left, current price, your max bid - Deal check: current price vs. your max, one line - Over your max: listed separately, dropped from watch - Ended: outcome, one line each rules: - Read only. Never place a bid, never snipe, never contact the seller. - Max bids are the user's. Ask once per item, reuse until it ends. - One alert per auction per stage. No repeat pings. - Run only on the confirmed cadence or when asked.
Estate Sale Scout
Thursday-night scan of weekend estate sales, ranked by your categories.
Tested in Museskillinstructionsworkflowreport-format
by Muse Skills editors · Written for this directory
ViewInstall the "Estate Sale Scout" skill. Its full source is below. Create it at ~/workspace/skills/estate-sale-scout/SKILL.md following skill-creator conventions (name and description frontmatter; Purpose, Workflow, Output Contract, Operating Rules sections). Then confirm it is installed and tell me the trigger phrases. --- SOURCE --- --- name: estate-sale-scout description: Scan weekend estate-sale listings Thursday night and rank them by your collecting categories, so Friday morning you know where to go. Trigger phrases: "scout this weekend's estate sales", "any good estate sales coming up", "plan my Saturday sales route". --- # Purpose Estate sales reward the early and the informed. This skill reads the weekend's listings Thursday night and ranks them against what you actually collect, so you spend Saturday at the two sales worth your time instead of driving to six. # Workflow 1. Ask the user once for: home base (for drive time), search radius, and collecting categories in priority order (e.g. vinyl, cameras, tools, mid-century furniture). 2. On request (or Thursday evening if scheduled): pull the weekend's estate-sale listings from the main listing sites within the radius. 3. Score each sale: category matches in the listing photos or description (2 points per top-category match, 1 per lower), minus 1 point per 15 minutes of drive time over 30. 4. Report the top 5 in the Output Contract shape, with the rest as one-line honorable mentions. # Output Contract - Weekend shortlist: top 5 sales, ranked: address, day/hours, why it scored (which categories matched), drive time - Honorable mentions: one line each for the rest - Suggested route: the order to hit the top picks on Saturday morning - Slow weekends: "Nothing in your categories this week." # Operating Rules - Public listings only. Never contact organizers or RSVP. - Scores come from the listing text and photos, not from assumptions. If a listing is vague, say so instead of inflating it. - Drive time is an estimate. Name the source (maps); never present it as exact. - One scan per request or per scheduled Thursday run. No drip-feed alerts through the weekend.