I have been working on one out of an Xbox Kinect but haven't been able to really get much value out of it. Most of the time I can take a few dimensions and draw it in CAD do some paper checks and go that way. Scanning and getting the models cleaned takes more time for me. I could see it with something with difficult geometry maybe. 2Kg of filament is 20-25 dollars for decent materials. You could get quite a few parts and trinkets out of one of those. I mean that's less than a few 2x4s now.