The most obvious of these is that removing Prize Cards from the game altogether would drastically alter the ways that Pokmon TCG build their decks
But don't sleep on Kor Haven either
It'd be just okay if the tokens created by Vren were measly 1/1s, but they scale with the number of rats you control
Bulk: $15/card, 25 card minimum, max declared value of $250, 30 day turnaround Economy: $25/card, no minimum, max declared value of $500, 20 day turnaround Standard: $35/card, no minimum, max declared value of $1,000, 10 day turnaround Express: $70/card, no minimum, max declared value of $10,000, 5 day turnaround WalkThrough: $150/card, no minimum, max declared value of $50,000, 3 day turnaround Unlimited WalkThrough: $150/card + 1% fair market value, no minimum, unlimited max declared value, 3 day turnaround CGC also offers the additional option of getting Sub-Grades where the card is assigned separate grades for centering, corners, edges, and surface in addition to its overall grade