How mystery slab boxes work
The seller fills a pool with graded cards and sells random pulls from it, by mail, on a livestream or as a digital pack. The pool's makeup sets your chances, not the box price.
Digital platforms like Collector Crypt and PrizePicks Packs sell a similar product as packs that reveal a vaulted card, often with a buyback offer.
What a seller should tell you
Look for the list of cards in the pool or at least the value tiers, how many slabs are in each tier, and whether pulled cards are removed or replaced. Ask what grading companies are included.
A seller who shows only the top chase card, with no counts, isn't giving you enough to judge.
Check the floor, not just the chase
Look up sold prices for the cheapest cards in the pool. Those are the most likely outcomes. If the common pulls are worth far less than the box price, expect to lose money on most boxes.
Run the cert number on any slab you receive, and compare its sold comps before accepting a buyback or reselling.
Mail-order and livestream boxes
For boxes sold on a livestream, Whatnot's breaks policy requires defined allocation criteria for breaks. Ask the seller to state the pool before you buy, and save a recording or screenshot.