I picked this up a few months back on the 360, and reckon it is the best fitness game (in particular for guys) so far.
The menu system is excellent, the body tracking is decent, and there is a lot of variety.
Apparently the 360 Kinect version is better implemented than the PS3 Move version.
Next cheapest I could see on the 360 is $43 (UK), and $39 for the PS3 (JB Hifi).
Link for PS3:
http://www.ozgameshop.com/ps3-games/ufc-trainer-includes-leg…