Sorry to hear this. I used to have a little lotus that got pronged like this about once a year on average as I parked it on the street. I soon learned that there are two types of garage. Ones that do loads of insurance claims and more local or specialist bodyshops that also do non-insurance or refurb jobs. The ones that do wall to wall insurance generally charged roughly 5x the price. Seriously exaggerated the amount of work done. It's difficult to tell, but do you really need a new bumper? You'll be amazed what they can do. My old lotus had a huge hole in the front clam that the insurance guys said at least 2K fix on one occasion. Got it sorted for £250 (admittedly that was the biggest difference I had between two garages)