It will be hard to find a stereo camera for < 100USD. Still, you can have a look on [Microsoft Kinect][1] and [Asus Xtion PRO LIVE][2].

There is no such stereo camera with a wireless video transmission in the market however you can make one using IEEE 802.11 transmission bands.

  [1]: https://dev.windows.com/en-us/kinect
  [2]: https://www.asus.com/3D-Sensor/Xtion_PRO_LIVE/