PSA set registry. Competition to have the highest graded collection of a set or player.
I'd much rather spend my money on a nice card than a cheap card that grades well. Also, the PSA set registry for a 1996 Topps Griffey Gem Mint 10 may be low, but that's only because people don't waste the money to have a card like that graded. I probably have 10 or so 1996 Topps Griffeys in my collection that would grade PSA 10. There are probably 50000+ Griffey 1996 Topps cards out there that would grade gem mint, so the whole PSA set registry for a card like that is a bit pointless, in my opinion.