I'd say 4-500 bucks max for Tamiya quality/fit/detail level in 1/8 scale, but it would have to blow Pochers out of the water. Not hard to do, IMHO. Forget silly things like rotating crankshafts. Just concentrate on visible details.
For subject matter, everyone will have a different answer. I could see spending that on a Duesenberg or other pre-war coachbuilt classic, or on a popular Ford other than a '32. For that kind of money, it should have a stock option as well as street rod.
I can't think of many new cars that would appeal to me enough to spend that kind of money.