My story is not quite as bad, but still sucked. Found a great stash of N64 stuff in boxes at GameRush last week (Paper Mario, Ogre Battle 64, Rocket). One game was Starcraft 64, which was only $7 and bought with credit anyway.
Get it home and look at it. The sticker looks kind of crumbled on the cart. I peel it back a little bit, and there's a Mission Impossible sticker underneath the Starcraft 64 one. Someone switched them at some point! And to make matters worse, the game didn't even work. Ended up bringing it back, but I sure would've rather had the game than $7 credit.