Question about buying rims?

I am a college student and purchased a used 2000 Volvo S40. My service man told me (and showed me) that the rims are somewhat bent. The previous owner must have lived in a city with terrible potholes or something. Anyway, my ride is not smooth, particularly at low speeds. Is there any place on-line I can find used rims (ones that aren't bent or defective in any way. Again I am a college student on a budget and am not to concerned about appearance, I just want my car to ride smoothly without paying several hundred dollars for aftermarket rims that I don't even care about. Any suggestions would be appreciated!!! Thanks!!!