I have no idea why so expensive, but MyAstroShop sells what appears to be the exact same scope+mount for $1200.
(Other places are selling it for even more.) The people running the shop are reputedly very knowledgeable about all things astronomical and honest about what they are selling, so it might be worth contacting them to find out more about the scope. Such a fast scope may be designed for deep sky astrophotography.
