car with heavy rust. Believe me, the door is not the only thing you will replace. If a door and a quarter are visibly rusty, it's in many other areas of the car. Maybe $1000 for the usable parts. There are rust-free cars available for that money. I have a guaranteed rust-free 82 733 I'd probably part with for that price. Needs brakes (complete) and a paint job, but you're looking at a pain job anyway. I'd look around. Rust is a real bummer.