I agree with THE TECH ask your dealership what shop they use for certified BMW body work (all BMW dealerships in larger cities have one they use ~ some of the staff is BMW trained they have BMW certification on the office /reception wall).
Then go there and let them give you an estimate ... I think it may be between $500- to $750- what you will be looking at.
On my 2011 AW I just traded last month I paid just shy of $3K for a rear bumper, paint and the bumper support. The bumper was $1K as was the support that was cracked. The rest was paint and labour ~ $1K ... so my $500- to $750- estimate would be fairly close for you.
Just make sure the shop you use is BMW Certifyed so you will get a good paint match.