I decided to sell my Nintendo Campus Challenge cartridge on ebay. It is the only 1991 Campus Challenge cartridge known to exist.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=370266968824

There is no reserve and the bidding starts at $0.99. A few people on nintendoage already expressed interest at $15K so it will be interesting to see where it ends up.

Good luck