Unit Price Comparator

What it does

Olive oil

| Product      | Size       | Price  | Unit price    | Verdict |
|--------------|------------|--------|---------------|---------|
| Small bottle | 16.9 fl oz | $8.49  | $0.50 / fl oz |         |
| Large bottle | 33.8 fl oz | $14.99 | $0.44 / fl oz | Winner  |

Total with recommended picks: $14.99
Difference versus the worst option: $1.99 less than two small bottles ($16.98) for the same 33.8 fl oz

What this one touches

Never places orders or checks live prices; it works only from the data you paste in. Never recommends bulk perishables beyond what you say you can finish.

Install

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

Full source

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

---
name: unit-price-comparator
description: Compares unit prices (per oz, per lb, per sheet) across stores and package sizes so you always buy the cheapest per-unit option. Trigger phrases: unit price, price per unit, bulk deal, cheapest per ounce, grocery math, compare sizes.
---

## Purpose
Sticker prices mislead. A family-size bag that costs more can be cheaper per ounce, and a sale item can cost more per unit than the regular brand beside it. This skill does the unit-price math on a shopping list and tells you which option costs least per usable unit, after adjusting for packaging tricks like concentrated formulas and different serving counts.

## Workflow
1. Ask for the shopping list and the candidate products or stores: paste labels, photos, links, or receipt lines.
2. For each item, collect the price and the net quantity (oz, lb, count, fl oz, sheets, loads, servings).
3. Normalize to a common unit per product type (per oz for coffee, per sheet for paper towels, per load for detergent).
4. Flag traps: shrinkflation (same package, less product), concentrated or diluted products, and club-pack quantities you cannot finish before they spoil.
5. Rank options cheapest-per-unit first, then give a final pick per item and the total expected spend.

## Output Contract
Reply with a table per product: product, size, price, unit price, and a verdict column naming the winner. Follow with two lines: the total for the full list under the recommended picks, and the difference versus the worst per-unit option.

## Operating Rules
- Never assume a size or a price; if a quantity is missing, ask or mark it unknown.
- Use the units the shopper thinks in; convert only when the comparison requires it.
- Do not recommend bulk buys of perishables beyond what the user says they can finish.
- Do not place orders or check live prices; work from the data the user provides.

More in Shopping

• Grocery List Deduper

  Merges every grocery list and recipe into one clean list with nothing counted twice.

  skillMerge of lists from every person, recipe, and note into one listDuplicate items combined with quantities added togetherItems grouped by store section so the shop is one passConflict flags when two entries disagree on brand or sizePantry check that drops what you already have at home

  by Muse Skills editors · Written for this directory

  ViewCopy install promptTo install the Grocery List Deduper skill, save the skill source below as ~/workspace/skills/grocery-list-deduper/SKILL.md, then tell Muse to use it whenever you have grocery lists from several people or recipes and want one clean list before you shop. --- SOURCE --- --- name: grocery-list-deduper description: Merge multiple grocery lists and recipes into one clean shopping list. Use when the user has lists from several people, recipes, or notes and wants one deduped list with quantities added together before shopping. --- ## Purpose Turn a pile of grocery lists, recipe ingredient lists, and stray notes into one list you can shop from in a single pass. The skill normalizes item names, combines duplicates with their quantities added together, groups everything by store section, and flags the places where two entries disagree so nothing gets bought twice or left out. ## Workflow 1. Collect every list: notes from each person, ingredient lists from each recipe, and any pantry or fridge notes. 2. Normalize the items: match the same item across lists even when the wording differs, such as tomatoes and tomato, and keep brand and size wording as the user wrote it. 3. Combine duplicates: add quantities together, convert units where the math is plain, and keep a note of which list each item came from. 4. Flag conflicts: when two entries disagree on brand, size, or amount, list the conflict and ask the user to pick, instead of choosing silently. 5. Apply the pantry check: drop items the user already has at home, and say what was dropped and why. 6. Group the final list by store section, such as produce, dairy, meat, pantry, and frozen, in the order the user walks the store. ## Output Contract - One shopping list with each item once, quantities added together, grouped by store section. - A merged-from note on each item showing which lists it came from. - A conflicts list with the choices the user needs to make. - A dropped list naming what was removed by the pantry check and why. ## Operating Rules - Never drop an item without saying so and naming the reason. - Ask when two entries conflict instead of picking one silently. - Keep the user's wording for brands and sizes so the list still matches the shelf. - Add quantities only when the units match or convert plainly; otherwise keep both amounts and flag it. - If a quantity is vague, such as some or a few, keep it vague and mark it as an estimate.

• Used-Car Shopper

  Turns a used-car listing into a plain verdict: fair price, red flags, and what to check.

  skillPrice check against similar cars listed nearbyRed-flag scan: title, accident history, and seller signalsTest-drive checklist for that modelPre-purchase inspection questions for a mechanicA plain verdict, with the evidence behind it

  by Muse Skills editors · Written for this directory

  ViewCopy install promptTo install the Used-Car Shopper skill, save the skill source below as ~/workspace/skills/used-car-shopper/SKILL.md, then tell Muse to use it whenever you find a used-car listing and want a plain verdict on the price, the red flags, and what to check before you buy. --- SOURCE --- --- name: used-car-shopper description: Judge a used-car listing before you buy. Use when the user shares a used-car listing, asks "is this a good price", "is this car worth it", or wants a test-drive and inspection checklist for a used car. --- ## Purpose Read a used-car listing the way a careful buyer would, so the decision rests on the price, the history, and the condition, not on shiny photos and a low monthly payment. The skill compares the asking price with similar cars nearby, flags the red flags in plain language, and builds a short checklist for the test drive and the pre-purchase inspection. ## Workflow 1. Collect the listing: year, make, model, trim, mileage, asking price, title status, and the seller's notes, plus the listing link. 2. Check the price: find similar cars listed nearby with the same year, trim, and mileage range, and note the price spread. 3. Scan for red flags: salvage or rebuilt title, a price far below the market, no service records, mismatched tires, rust in the photos, or a seller who will not share a vehicle history report. 4. Look up the model: common faults for that year and model, and the repairs that tend to cost the most. 5. Build the checklists: a test-drive checklist for this car, and the exact things to ask a mechanic to inspect. 6. Give the verdict: fair price or not, the red flags, and what would change the answer, with the evidence shown. ## Output Contract - A price comparison: asking price against similar listings nearby, with the range and the sources. - A red-flag list, each flag named plainly with where it appears in the listing. - A model note: common faults for that year and model, and the costly repairs to watch for. - A test-drive checklist and a pre-purchase inspection checklist for a mechanic. - A plain verdict: buy, walk away, or negotiate, with the reasons and what would change it. ## Operating Rules - Never tell the user to buy a car; the verdict is advice, and the buy is the user's call. - Never call a price fair without showing the comparable listings behind it. - Never invent a vehicle history report, an inspection result, or a price; if a fact cannot be checked, say so. - Treat a price far below the market as a warning, not a bargain, until the reason is clear. - Keep the checklists short and specific to this car, not a generic list.

• Ratings-First Product Comparison

  Compares products by ratings and reviews first, so the best-reviewed pick wins.

  skillRatings and review-count check for each candidateReview summary that separates real complaints from noiseSide-by-side table: rating, review count, price, and key specsWarning when a product has too few reviews to trustA pick with the reasons, in plain language

  by Muse Skills editors · Written for this directory

  ViewCopy install promptTo install the Ratings-First Product Comparison skill, save the skill source below as ~/workspace/skills/ratings-first-product-comparison/SKILL.md, then tell Muse to use it whenever you compare products and want the ratings and reviews checked before the price. --- SOURCE --- --- name: ratings-first-product-comparison description: Compare products by ratings and reviews before price. Use when the user says "compare products", "which one is better rated", "check reviews", "best reviewed", or asks which product to buy and wants ratings checked first. --- ## Purpose Put ratings and reviews first when comparing products, so a low price on a weak product does not win by default. The skill checks the star rating and the review count for each candidate, reads what buyers actually complain about, and only then looks at price, so the pick rests on how the product holds up in real use. ## Workflow 1. Collect the candidates: product names or links, plus what matters to the user, such as size, fit, or durability. 2. Pull the ratings: star rating and review count for each candidate, from the merchant page, and note the source. 3. Read the reviews: common praise, common complaints, and recurring defects, with the worst recurring complaint named plainly. 4. Flag thin evidence: a rating built on only a handful of reviews, or a high rating with no written reviews behind it. 5. Build the table: rating, review count, price, and key specs side by side, with the source for every number. 6. Recommend: the best-reviewed pick that fits the budget, with the reasons in plain language, and say when no candidate earns a recommendation. ## Output Contract - A ratings table: star rating and review count for each candidate, with the source. - A review summary: common praise, common complaints, and the worst recurring defect. - A thin-evidence flag for any product with too few reviews to trust. - A side-by-side comparison: rating, review count, price, and key specs. - A pick with the reasons, or a plain statement that no candidate earns one. ## Operating Rules - Never invent a rating, a review count, or a price. If a number cannot be found, say so and mark the row as unverified. - Treat a small review sample as a soft signal, never as proof; say how many reviews the rating rests on. - Check the price only after the ratings are in, so a cheap price cannot hide a weak product. - Note when a listing looks sponsored or the reviews look planted, and say the final buy is the user's call. - Keep one currency and one unit through the table, and state both.

• Marketplace Listing Builder

  Turns item photos into a ready-to-post marketplace listing priced from recent sales.

  Tested in MuseskillItem identification and details from photosPrice grounded in recent sold pricesOne condition question photos cannot answerReady-to-post title and descriptionBundle and repricing suggestions

  by Muse Skills editors · Written for this directory

  ViewCopy install promptTo install the Marketplace Listing Builder skill, save the skill source below as ~/workspace/skills/marketplace-listing-builder/SKILL.md, then tell Muse to use it whenever you share photos of an item you want to sell. --- SOURCE --- --- name: marketplace-listing-builder description: Turn photos of an item into a ready-to-post listing for Facebook Marketplace, Craigslist, or eBay, with a price grounded in recent sold prices. Use when the user says "sell this", "list this for me", "what is this worth", "write a listing", or shares photos of an item they want to sell. --- ## Purpose Take the slow part out of selling household items: turning a few photos into a listing with a fair price. The skill reads what the photos show, checks what similar items actually sold for, asks the one question a photo cannot answer, and hands back a title, a description, and a price the user can post as is. ## Workflow 1. Look at the photos: identify the item, brand, model, size, color, and any visible wear, damage, or missing parts. Note anything the photos cannot show. 2. Ask the one question photos cannot answer: does it work, and what is its true condition? Wait for the answer before drafting. 3. Check recent sold prices for the same or closest matching item on the marketplace the user names. Use sold prices, not asking prices, and say how many comparable sales the price rests on. 4. Set a price: a starting price for a quick sale and, when the gap matters, the higher price a patient seller could ask. 5. Draft the listing: a title with the words a buyer would search for, and a short description covering what it is, its condition, what is included, and pickup or shipping terms the user gives. 6. Check the value floor: if the item is worth too little to sell alone, suggest a bundle with related items instead of a solo listing. 7. If a listing sits without interest, draft repricing moves: a price drop, a title change, or a bundle, with the reason for each. ## Output Contract - An item summary: what the photos show, plus anything they cannot show. - The condition question, asked before any draft, and the user's answer reflected in the description. - A price with its basis: the comparable sold listings it rests on. - A ready-to-post title and description the user can copy. - A bundle suggestion when the item is worth too little alone, and repricing drafts when a listing sits. - Nothing is posted. The output is a draft for the user to review and publish. ## Operating Rules - Never publish, edit, or delete a listing, and never message a buyer or seller. - Never invent a detail the photos do not show. Mark anything unknown as unknown and ask. - Base prices on sold listings whenever they exist. If no comparable sales can be found, say so and label the price as an estimate. - Describe condition honestly, including flaws the user confirms, even when a softer wording would sell faster. - Keep personal details out of the listing text: no addresses, no phone numbers, no names.