Gosh driver, this is variable question. So much depends on what kind of condition the bike iswhen you start. I was pretty lucky in finding a bike that had an amature restoration about 15 years ago and is 100% complete. To make it useable, I could have gotten by just in cleaning the fuel system & driving it, but I'm tweaking out the things that the last guy didn't work on (tail light lens is faded clear, wheel spokes are rusty, etc). All told, i'll probably be in for a couple hundred bucks on top of the 1500 I paid for it (not counting replacing the tires). On the other hand, if I wanted to do a 100 point restoration & contracted out all the work, it could easily exceed 4 grand.
Mike Sal