There is a tool you can buy that can straighten the fins, it's called a condenser comb. You see them all over, at the usual parts houses, snap-on trucks, etc. I would straighten before I bought new, as long as the tubing is still in good shape. Have you had the a/c serviced recently? Now days they can suck out all the freon,clean and measure it,and refill the system to make sure you have the right amount of freon. That and the fin comb would be where I would start. fwiw