Let's put it this way, there isn't a business plan in existence that makes financial sense to restore a vehicle.
It has to be for the love of car.
I'll agree that the drivetrain can get expensive, but it is also the thing that most people can do themselves (save machine work). Putting on a show quality paint job requires great skill and infrastructure that is outside the realm of most shadetrees. Therefore, bodywork is the most expensive area IMHO. When done right it's also one of the most rewarding.
