DealScan — Marketplace Deal Evaluator

About

DealScan tells you whether a Facebook Marketplace listing is actually a good deal — in seconds, without leaving the page.

Open any listing, click Evaluate, and DealScan reads the item and gives you a clear, no-nonsense verdict:

• Deal score (0–100) and a rating: Great Deal, Good Deal, Fair, Overpriced, or Avoid
• A clear call: Buy, Negotiate, or Pass
• The item's fair used-market price range
• A suggested offer to make
• How the asking price compares to market — above or below, and by how much
• A one-line summary of the bottom line

WHY IT'S DIFFERENT

• Reads the real listing. DealScan verifies it's evaluating the exact item you're looking at. If it can't read a listing confidently, it tells you and skips it rather than showing you a wrong number.
• Looks at the photos. It checks the listing's images to judge real condition and flag stock-photo scams.
• Knows cars. It pulls mileage and year so vehicle prices actually reflect them.
• Stays out of the way. A side panel keeps up as you browse from listing to listing, with a floating Evaluate button right on the page.
• Keeps a record. Save evaluations to a searchable history or add listings to a watchlist, and export your history anytime.

WHAT YOU NEED

DealScan runs on your own Anthropic (Claude) API key — you enter it once in the extension's options. New Anthropic accounts include free credit, and each evaluation typically costs under a cent, so that free credit covers hundreds of scans. Nothing is billed through the extension; you're always in control of your own usage.

Prefer cheaper or more accurate? Settings let you turn photo analysis off for the lowest cost, or turn on live web search for the most up-to-date pricing on big purchases.

PRIVACY

Your API key is stored locally in your browser and is only ever sent to Anthropic. Listing data is sent to Anthropic solely to produce the evaluation. Your history and watchlist stay on your device. DealScan has no servers of its own and collects nothing.

DealScan only activates on Facebook Marketplace listing pages.