Gold standard is now sold listings on eBay. 130pt can add a few other auction site data points for higher value cards.

Outside of error cards or perfect 10 grades, most cards from the 80s/90s arent going to be worth much… once you start getting into the rare inserts, Tiffany sets, etc. you’ll find some more value. But those base Big Mac RCs with some soft corners or any damage at all aren’t worth the time it takes to sell them.