This isn't at all off from Nintendo's pricing, and being the first to use this style of control, they set the "value" of it.
WiiMote and Wii Motion Plus will run about 50$
Nunchuk will run you an extra 20$
So you're still running about 70 dollars.
If I remember right, Kinect supports at least 2 people, so you're paying about 75 per person for that as well.
Motion controls have a pretty hefty admission price, no matter which console.
What's really concerning with Move is why so many shots have people using 2 of the main controller. That's clearly two lightbulbs in the "archery" shot, not a navi controller.
If 2 controllers are going to be needed per person for some games, they'd better be up front about it.
(Could you imagine having to buy 8?)