The FXX is a concept case study based on the Enzo platform. One buys into the testing program more than they do the car itself. It's a way for Ferrari to keep the next supercar less race car driver oriented. I forget what the testing term is, but I wanted to say 2 years rings a bell @ a cost of over 2 million dollars.
Edit: I just did a little bit of researching on the net. It appears I goof'd the part about not owning the car. I thought I remember reading that a more than a year ago. Oops!
So yeah, for roughly 2 mills ... it's yours. Still the client R&D concept is indeed a big part of the FXX project.