Here is my experience with previous cars: it is nice to find a local independent shop that you can see has worked on and mainly works on BMWs and start taking your car there... it pays off in the long run to form a good relationship with such shop, even if you end up paying 10% more now.

Here is a quick search on your local craigslist that 'claim' they do only BMWs... if these are shops, you can drop by and talk with them perhaps?

http://boston.craigslist.org/search/...BMW&srchType=T

Here in SF Bay area, independent shops are advertising complete front/rear brakes with BMW/OEM parts for about $800 or so.

With brakes, I would go with genuine BMW parts myself, but that is just me.