I know this is about trading card games and not board games, but I would say they’re very close in principle, considering the complexity of games like Magic. I recently discovered the mysterious world of “grading”, in which services like PSA will grade your card as to add some felt value to the card itself, because of its rarity and how near to mint it is.
We’re talking about services that will grade the same card differently three times if you send it back, because of course they have no practical way of having an absolute meter for every possible imperfection.


Gruhn Guitars started this trend with vintage instruments, too. It inflated the market value of old instruments.
Mint, excellent, very good, good, fair… Fuck off. It’s worth what someone will pay.
Kelly Blue Book, etc.
And don’t get me wrong, a price guide isn’t all bad.