Cheap would be good. I might even get in for a few if they where. I dont do super macro/helicon focus/magazine article quality/gotta be 100% CORRECT photography or modeling. I prefer just to watch my trains run and enjoy that part of the hobby.
Are these the same cars as the Whitewater Bldg Materials orange cars? if so, I'd go for 1. Depending on the price. $25-30 max/car.