I hate to say this, and I'm sure it's painfully obvious to the veterans here, but there is a presumption (not limited to old cars) that the finished product must be worth whatever it cost to fix.
This makes for busted marriages, foreclosures, ruined friendships, etc.
I dimly remember someone's mod of a price/time estimate for an engine rebuild: "Make it more realistic - add $5,000 and 2 years".
