Doc Freieri had one back around 55, saved up for a year to buy the thing and it cost near a week's pay. He bought it to work on his rifles, and wished very fast he hadn't.
It got too hot to hold in about 5 minutes, and was too fast for both buffing and the steel the tools that came with it so they burned.
Doc was clever though, he talked about that tool every chance he had, and went to holding viewings in his living room. His place looked like a funeral home on nights guys stopped by to see the tool. Doc was king of his neighborhood because he owned quite a few power tools.