MakerBot has one and I saw one person on Youtube that used it do a pretty good job on a simple model.
Im sure there will be many more coming out at good prices.
I plan to make some small gear parts for old stuff that need some new ones but they are not made anymore.
The 3d scanner would save lots of time designing.
Scanning small gears is something the makerbot scanner could never do, the resolution of that scanner is way to low,
you would need a sub 0.1mm scanner to maybe do that, and the Einscan-S is the cheapest 0.1mm scanner at the moment.
Why don't you do it the old fashion way, use a black marker and color just one side of the gear, lay them on a old flatbed scanner, and scan at highest resolution,
you would just need to trace the image in a CAD program, and make it and size or thickness you want
Yes if its flat on both side I could just scan it on a flatbed scanner and then extrude it up to the right thickness.
But if its a different shape the scanner would help. I will have to keep looking.