Thats a lot of money even if its american
That would be because
1) It's the original
2) It spent about 5 years in Storage, and then about 18 on display at Back To The Future: The Ride at universal studios in Florida. For that reason alone I would buy it, just to have some memorabelia of the best simulator/imax ride ever built.
3) It is worth A LOT. Almost all film props sell around that price mark, especially ones from popular films.