Yes.  They(NaturalPoint) have a sales going on, if you buy 3 or more OptiTrack cameras they are $200 each.  So you are right when you get six of those and other equipments like usb hubs/cables, tripods, total cost might be close to $2000.  That is why I am a little hesitant about releasing my software.  I don't want people to spend that kind of money until my software works perfectly. 

By the way I think it is still much cheaper than current commercial systems.  The cheapest optical mocap system I found was metamotion's MotionCaptor which is like $45,000(http://www.metamotion.com/captor/motion-captor-comparison.htm)