I have a copy of a game called "Super Series Big League Baseball" that was intended for use with the keyboard add-on for intellivision. The game has never been played, the overlays are still joined from being die cut. The cartridge says World Series Baseball as do the overlays, but the instructions have the same title as the box. I guess there was some copyright infringement and Mattel had to change the name.

Does anyone know the value of this game in this condition? The only other game image I've seen doesn't show the keyboard component at the top of the box.

Thanks for any help.