Because they say it’s still “New in box”.
Some games are worth a lot if the have never been opened....I really don’t think this is one of them.
An original Super Mario Bros for the NES (a stand alone game cartridge, not the one that came with most of the NES’s that had other games like Duck Hunt included) that had never been opened and was in pristine condition sold for over 100k. If I remember correctly, this version of SMB was only available in the New York area when Nintendo was doing limited sales of the NES for the US market.
So now some people see an unopened old game and see dollar signs.