The cheapest option is buy a lathe and convert it yourself. But it is also the hardedst option too. There is a pretty steep learning curve.
the advanteg with cnc machines is making many of the same piece. You get the code right and them you bulk produce a part. You would only need to use a cnc for one offs if the part is complex in design. It takes a while to make good gode and a few trials b4 you get it right. This is why one off parts are not that good for cnc.
Anyhow, I am sure by reading through this forum you will get a flood of information.
Welcome
Being outside the square !!!