When I see how cheap aftermarket parts are, I see why the insurance cos. do what they do. I was fixing some rust on my 1998 Nissan, and my uncle goes why fix it, get a replacement aftermarket fender. It costs $38 at the body shop, and it's not the cheapest replacement fender, it's middle of the road. There is one for $70 and another for $29.
Imagine having insurance put a $38 retail fender on the car, it's probably under $20 wholesale. As opposed to an OEM being $308.73 retail, or probably 60% less wholesale. So insurance is trying to pay $20 for the fender, as opposed to the whopping $123. When you look at how much you pay in premiums, I'd hold them to the $123 if I could.