PrimeSense (the company behind the Kinect IR technology) had a competitor at the time called 3DV systems (or something like that), that made an RGBD TOF camera that worked way, way better than the kinect - but they ran into financing problems, and were bought at-cost by Microsoft (something like $30M, which was the investment). That was in 2007, and even back then they were able to produce them for ~$300/BOM if I remember correctly.
At the time, everyone assumed MS just bought them to shut out competitors - but it appears they actually use the thing.
And I was thinking about 3DV Systems' [1] product called ZCam [2]. I wasn't aware of the Canesta deal - apparently, MS cornered the market of depth cameras. Personally, I think this deserves some kind of regulatory anti-trust action. But that's just me.
At the time, everyone assumed MS just bought them to shut out competitors - but it appears they actually use the thing.