It would depend on the completeness, correctness, and condition of the car to be restored.
A good working number would be $100,000.00 to $ 125,000.00. (plus the car)
If you are writing the checks, you certainly don't do it to make money, but rather to get the car you always wanted into the condition you wanted it in.
Better, and far less expensive, to purchase one that is close to your dream car as you can find.
Much better way to go!
(unless of course you are one of our esteemed personal restorers on this site, that enjoy doing it and only write checks for parts!)
Marty