Also, what scale do you use to compare costs? From the fact that you call Kinect (sold ~18M [1]) "one of the most popular consumer electronic devices in history" and Move (sold ~15M[2]) "has not taken off" it appears that either you are using some kind of highly non-linear measure or are better informed than almost everybody else.
[1] http://en.wikipedia.org/wiki/Kinect#cite_note-18-million-1
[2] http://en.wikipedia.org/wiki/PS3_Move#cite_note-15_million-4