There's at least 6 or 7 known copies of the Genesis game last I checked, and these were for the second Blockbuster Championship. You could choose to play either the SNES games or the Genesis games for the competition. I used to try keeping track of them as they sold between collectors but it was getting a bit difficult as nobody else was trying to keep track of who had a copy and who it got sold to.
Good luck on the auction, if it sells for your asking price more power to you.