A super-rare Allen Iverson card just hit the auction block, but it could very well be out of most collectors' price range ... 'cause someone's already bid $150K!!
TMZ Sports has learned the 1997 Skybox E-X 2001 Essential Credentials Now Iverson piece went up for auction at Heritage Auctions on New Year's Day ... and it's already received an aggressive six-figure bid.
It's a huge number .