I started flipping contemporary road bikes to finance my own cycling hobby few years back. I've only been doing it in frequently, but when the right bike comes along....
Right now, I'm up about ~1200 plus my current bike. Haven't flipped a bike in 4 months though...
Here are my past bikes:
http://www.bikeforums.net/showthread...=#post14462817
I imagine if you live in the right place, you could probably do this sort of thing for living.