i had that happen to me, my car was only worth £5500-£6000, needed new bumper, smash panel, bootlid, interior plastics and carpets, part of the boot floor cutting out and a new one being welded in, spraying on bootlid and bumper.
i thoiught mine would have been a write off, and so did 2 body shops that i took it to for quote before the insurance got it but they fixed it without questionning.
i think it depends on the garage aswell, if they have some spare parts for a particular car then they may give the insurance a cheaper deal for the fix, as mine is a standard clio etc the parts are easy to find so wasnt much of a problem, but if it is a rarer model, like said above the parts will be harder to find.