Can a bent rim on a car be fixed?

This depends on the damage, material (aluminium, steel) and design. If the damage isn't severe it is definetly cheaper to fix at a auto-garage with the proper equipment than buying a new one.

I cracked an aluminum rim. It was split about 3 inches and dented it. I found a garage that would staighten it, reweld the crack, and grind it back smooth for $75. A steal for me as this rim wasn't made anymore. Oddly enough the shop had no real advertising, everyone knew them by Word of mouth. Hope this helps.