The custom builders that have those waiting lists also have years of experience behind them.

While I don't feel qualified to answer the OP because I only have a couple of frames under my belt, there is only one scenario where I see myself building frames for a living, and it goes a little like this:

* I'm at the point where I've built 25-30 frames and have the fundamentals down cold.
* I have added to my tools at the very least (1) an O-A or O-P torch and (2) some form of jig, most likely one built from 8020 or a Bringheli alignment plate.
* I'm building 6-8 frames per year for friends, family, and acquaintances on nights and weekends.
* I have enough orders "in the pipeline" that I can't fill them at the schedule I'm building within the next year (this is as far out as I would be comfortable having a waiting list)
* I'm able to charge enough for frames, and I've gotten efficient enough, that I'm making about $25/hr before taxes for my time
* I'm only building frames that I would ride, so mostly classic racing, cross, rando, sport touring, constructeur type frames. Nothing crazy, nothing unsound, nothing that I wouldn't put my name on.

So, I figure with the most basic of finishes and fairly mundane frame tubes, I'd charge about $1500 at the very lowest.

Realistically, I won't ever "go pro", and the only time I see myself building frames full time is once I retire. I am, however, a high school teacher, and have summers "off" (in quotes because I always work during the summer) and could see building 3-4 frames per summer.

With that said, I don't see how a person who has never evn built a frame could even be thinking of going into business as a framebuilder. That's got disaster written all over it.

Pete