I own a metal lathe and 2 wood lathes. It would really stink to not own a lathe.
Say I need a pulley, a shaft, a bushing, I just make it.
I can even turn a part in wood for a pattern, make a mold, cast it in metal and machine myself new parts.
A lathe is like a pick up truck, once you have one you don't ever want to be without one.