Movies have been made about robots making other robots. Like innovator Henry Ford, the MakerBot company realized that in order for this technology to take off, it needs to affordable to the customer. From the mind of a mechanic, I can see the value of this machine. Need a bushing, make it need a special part make it. Inventing something, make it by simply using available software to make a 3D picture, and there it is.
These machines can be purchased to sit on your desk for under $3000, or if you can build it yourself much less.