CardComps — Card Values for eBay

Instant eBay sold-comp fair value + margin on eBay sports-card listings.

CardComps puts a fair-value estimate on every eBay sports-card listing, so you can tell a deal from a trap without leaving the search page. Each result gets a rating chip as you scroll — Excellent, Great, Good, Fair or Bad — based on how far under fair value the asking price sits. Click the Value button on any listing for the full picture: what that exact card has actually been selling for, the range it trades in, how recently, and your margin. REQUIRES AN EBAY SIGN-IN eBay shows completed and sold listings only to signed-in users, so CardComps needs you signed in to eBay in the same browser. It never sees or stores your credentials — requests ride your existing session, exactly like any other page you load. If you are signed out, the extension tells you so rather than pretending the card has no sales history. WHAT YOU GET • Fair value from real sold comps, not wishful asking prices • A deal rating on every search result, filled in as you scroll • The individual sales behind every number, with thumbnails, linked to the real sold listings • Gross and after-fee margin against the current bid • Price-over-time chart with a trend line • Grade and Variant menus — including free-text entry — to price the exact card in front of you • Works on search results and on individual listing pages BUILT TO BE HONEST Matching cards is the hard part, and a confident wrong number is worse than no number at all. Before counting a sale as a comp, CardComps checks the release year, print-run serial, autograph status, product line, grade and parallel. When comps disagree too much, or there simply are not enough of them, it says so instead of guessing. Best Offer sales are counted at 85% of asking — eBay hides the real accepted price — and flagged wherever they appear. Sold data covers roughly the last 90 days, which is as far back as eBay's public search goes. PRIVATE BY DESIGN Everything runs inside your browser. There is no server, no account, no tracking, and no data collection of any kind. The extension caches the sale records it reads from eBay on your own device for a day so it does not re-request the same searches; nothing is ever sent anywhere.