The seller has a ridiculous amount of other sealed stuff for sale as well. Lots of Game Boy Color, some Game Cube, tons of SNES a boat load of NES and more. All extremely nice items, and they come with the price tags you would expect.
You can also check out what has been sold so far. NES Punch Out for $700.00, Actraiser 1 /2 for SNES at $499.99 and a few others.