How to Value Sports Cards Using eBay Sold Comps

Why sold comps win

Asking prices are wishful. Sold prices are real. Every card on eBay has two markets: what sellers list for, and what buyers actually pay. The gap is sometimes huge — asking prices for a 2018 Luka Dončić Prizm PSA 10 often run 30–60% above what completed sales close at. Sold comps cut through hype and tell you what the next buyer is realistically going to pay.

The 5-step method

1. 1. Match the card exactly. Same player, year, brand, set, card number, parallel, and grade. A 2020 Mosaic Silver Justin Herbert is not the same card as a base Mosaic Herbert.
2. 2. Pull 60 days of sold comps. On eBay, filter completed listings to "Sold" and the last 60 days. You want recency — the card market moves weekly.
3. 3. Take the median, not the mean. One outlier auction can drag the average. Drop the high and low, then use the middle value of the remaining sales.
4. 4. Adjust for condition. Raw cards sell at a steep discount to slabbed cards. Rough guides: PSA 9 ≈ 2–4× raw, PSA 10 ≈ 2–10× PSA 9, BGS 9.5 ≈ PSA 10 for modern, BGS 10 (black label) is its own market.
5. 5. Apply a parallel multiplier. Numbered parallels carry premiums — Silver ≈ 2–4× base, Gold /10 ≈ 10–30×, 1/1 is auction-only and depends on the player's heat.

Common traps

• Best Offer accepted sales show the asking price, not what the seller actually accepted. Treat them as a ceiling, not a comp.
• Auction snipes on low-watch listings often close below market. Look for at least 3 bidders and 5+ watchers before trusting an auction price.
• Pop-report spikes. A PSA 10 worth $400 last month can halve overnight if 200 new 10s hit the registry. Always check the latest pop count before pricing.

A worked example

Say you own a 2018 Panini Prizm Luka Dončić #280 PSA 10. Pull the last 60 days of PSA 10 sold comps: you find sales of $610, $580, $625, $640, $595, $720, and $560. Drop the $720 and $560 outliers. Median of {$580, $595, $610, $625, $640} = $610. That's your fair market value today. Track it weekly; if the median climbs above $640 for two weeks running, the card is in an uptrend.