I'm curious to know how Gamestop will evaluate the value of the PSA graded cards. They already low ball you on the trade value on games, I would imagine they will do the same with cards.

GameStop will pay a maximum of $500 in cash or in-store credit.
Graded Collectibles trade offers are hassle-free and the offer is final.

What are they going to do with the cards? Resell them?

https://www.gamestop.com/gradedcollectibles