I have one set up like this in my garage. Father has Bridgeport, Surface grinder and lathe all set up this way. I don't think he spent more than $100 each on his VFD.What Tom said. A friend of mine has one on his Bridgeport. You end up with 2/3 the HP of the motor rating if I remember correctly.
We use them all the time at work too but for different reasons. With a VFD you get no derating. The old rotary phase converters had to be derated. VFD gives a perfect 3 phase thanks to the magic of electronics.