To do this right you have to keep track of every little purchase you do related to your project. I'm talking about bolts, nuts, sandpaper, grinding discs, body putty, primer, paint, wire, wire connectors, any special tools you might have to buy just for a job on it, etc,
You would be AMAZED how much you spend of little stuff. Every time I run out to Ace Hardware or Home Depot for some small parts the bag is very small and I end up spending $ 25- $100. Nobody counts that stuff in, we just tally up the headers, motor parts, tires, etc....the big stuff.
One time I drove my T to a gas station and a guy came up and was admiring it. He said, "Some day I should drop off $ 10,000 and let you build me one of these !" When I told him I probably had twice that in parts, and I did all the labor myself, he looked at me like I was nuts. But that is the reality of building a car from the ground up.
Don