The markup is somewhere around 8.7% on new car MSRP and they've even thrown in cash incentives on this brand new design. Given that it's a demo I would say you should be able to demand a pretty competitive price vs new.
F25 X3 N20:
2010 B8 A4 2.0T quattro (current)/
2013 F25 X3 x28 N20 (babymobile)