It's like they say in racing... "The best way to make a small fortune in CS restoration is to start with a large one".
Be sure that what you create will have value exceeding the time and money you put in. Frequently this does not turn out to be the case. But then, people still go to Vegas thinking they will come home with more money than they went there with.
Seriously, I've had friends who have put money into their Bimmers, far in excess of what they later sell the car for. If you want to go upside-down, feel free, just know that from the beginning. One way to do so is to be in touch with experienced guys as named in the previous post, who can advise as to the appropriateness of contemplated actions.