What is a comp when buying Pokemon cards?

A comp, short for comparable sale, is a recent completed sale of the same card, in the same version and the same grade or condition, that buyers use to judge whether a listing's price is fair. The word "same" does all the work. A PSA 10 sale isn't a comp for a CGC 10 or a PSA 9, and a holo's sale isn't a comp for its reverse holo.

Asking prices on live listings aren't comps either. They show what sellers want, not what buyers paid.

Before you buy one

• Use the Sold filter. On eBay, the Sold items option in Advanced Search shows completed sales. eBay may ask you to sign in before it shows them, so sign in first.

• Read a Best Offer sale as a ceiling. An accepted Best Offer can hide the real price. eBay's help pages don't say how an accepted offer appears in sold results, and members of eBay's community report that the accepted amount isn't shown, so treat the price you see as an upper bound.

• Collect several. One sale is a data point, not a price. Gather several recent sales of the exact card and grade, note the date of each, and leave out any that look like a damaged or mislisted copy.

• Ask which sale they mean. Collectors and sellers say "comps", "sold comps" and "last sold". When a listing leans on one, find that sale yourself before you take its word.

ChaseBoard doesn't pull sold prices for you, but each card tile has a Sold link that opens eBay's own sold search for that card, so the first step is one tap.