My experience is that maintenance costs increase exponentially with regard to the car's value. On my daily driver Mercedes, I'm perfectly happy to use aftermarket parts. On my Barracuda, I spend months researching every repair, and more months hunting for NOS parts. It doesn't pay as an investment unless you are in a position to do most or all of your own work, or the car is something really special.

Classic car buyers tend to buy their childhood memories. So at times you will see better prices for an ordinary 1965 Mustang than for a '31 Pierce Arrow. As generations come and go, their cars tend to gain and lose value.

Classic car values also have a relationship to the stock market. They peak at the end of bull markets, when there's lots of cash available for self indulgent hobbies.