How should I address my lower quarter rust on a budget?

You really need to get behind that rust. If you notice that much damage on the exterior, then it is much worse on the inside... cutting and adding new metal is the only way to go. If you bondo the metal, you will be trapping the moister behind the quarter panel. It will come back an visit you often. If you want to please your eye on a budget and stall for some $cash$ to come your way. Then Bondo is the way to go. You need to find out where the moister is coming from or how wet dirt is cumulating. Most likely your back window gasket. Good luck on your fight against RuSt!!!:bball: