You aren't even required to get the damage fixed at all, unless it's such that the vehicle isn't road worthy. It's entirely your choice to get the repairs fixed however you wish, or pocket the money and live with the damage.
I had my car broken into years back and the head unit stolen out of it. I originally bought the head unit at a pawnshop for around $100. The Insurance Company valued a comparable new unit at $400, appraised a new center console (since they pretty much tore mine apart getting the radio out) at $900, and replacing the busted window at $700. I went back to the pawnshop and got another $100 radio (probably stolen out of somebody elses car), patched up the center console myself, and got a replacement window from the junkyard for $50 and replaced it myself. Pocketed the rest of the money.