Kinect

The announcement came during Microsoft’s final CES keynote address.   Going on sale February 1, 2012. MSRP: $249.00

The device will go on sale in 12 countries, (United States, Australia, Canada, France, Germany, Ireland, Italy, Japan, Mexico, New Zealand, Spain, United Kingdom).
Suggest retail price for the device is $249.00.

Why so much more for the device than the XBox version you ask?  Near Mode:  a ton of time and extra effort has gone into the unit to optimize it to work at of distance of 20 inches.  Roughly where one is sitting at the computer.

Sources: Gizmodo, MSDN