Value each card at its exact grade
A raw card and a graded one are different assets, and a PSA 9 versus a PSA 10 of the same card can differ by multiples. So value each card by its specific identity: year, set, player or character, card number, grader, and grade. Anything less is a guess.
Use realized sales, not asking prices
List prices and "for sale" comps are noise — only completed, realized sales tell you what a card is actually worth. Look at recent sales of the same card and grade, and weight by how often it trades: a card that sells frequently has a confident value; a rare one has a wider range.
Slabline automates exactly this — it aggregates comps across eBay, Heritage, Goldin, and PWCC and shows the sales volume next to each value so you know how much to trust it.
Total it — and keep it live
Add the per-card values for a collection total. But a total is only as good as its date: hobby prices move fast, so a number from last season can be far off. Scan your slabs into Slabline and it values the whole collection from live comps and tracks the total over time — free for up to 25 cards.