this is my opinion, feel free to ignore it
i don't give an ass butt (as in, the bottom part of a donkey) about grading, i wouldn't pay a dollar more for a game entombed in a transparent plastic brick, and i think that if you are willing to pay for this service, you deserve the risk of getting scammed by people looking for quick riches
also, this whole thing drives prices up while providing fake security so it's a lose-lose for me
i could send mismatched games and they wouldn't know, i could send regional variants and they wouldn't even know about them