I spoke to a vendor at the swap meet over the weekend who claims to own several sealed NES games. The only reason he's held onto them, he claims, is that the value of the games is relatively low. One of the games he mentioned was a Challenge Set Super Mario Bros. 3. He said the game is not sealed like a typical NES game, but sealed by tape. I have seen the challenge set tape on SMB3 before, but is it relevant that the tape has not been tampered with? Assuming the game is near mint, is this an item worth grading? Or is it even gradeable? I wish I had more information or images, but I'm just going by word of mouth. I asked him to bring his box of sealed games next week so I could give him a better idea of what he has.

This probably belongs in collectors corner. Not sure why I posted it here, sorry! 

I think those challenge set SMB3's are gradable, but the demand is less than for a "normal" sealed copy.

Thanks Blarky, pretty much all I needed to know.