there's a huge market for one-of-a-kind/prototype/exhibition/demo stuff, there's a place near my house that specialized in oldschool/hard to find games called Digital Press. They put out a VG pricing/rarity guide every year, one sec and I'll find the link...
Classic Video Games - Digital Press
Digital Press Video Game Collectors Guides
lulz... for 17.5k it had better do more than that.