A factory-sealed copy of Super Mario Bros. sold on eBay yesterday for over $30,000. This is one of the most common games on the NES, so this is a head-scratching development.
Why did this go for so much? Honestly, I have no idea and can only speculate. Many other factory sealed copies are available on eBay ranging from a few hundred to a couple thousand dollars. Bidding looks legitimate and the seller is a well-established and respected seller with over 40 thousand feedback score.
Perhaps bidding frenzy caught hold of some people. Maybe a factory sealed copy from a trusted seller is worth that much more to bidders? Who knows, but its one of the craziest prices I've ever seen a single game fetch in my years of being in this hobby.