The prices could be in that range, indeed. Sounds reasonable. The subcontroller has no motion sensing, but it has a lithium battery so I doubt it will be any cheaper than a nunchuk.
Just a little note: the subcontroller is most probably not in the start pack because its use is completely optional, as in you can always use a DS3 or Sixxaxis when a subcontroller is required by the software (see footnote 2 of Sony's official statement).
Thus it makes sense to offer a pack with the least amount of hardware that is strictly needed.







