There's an excellent wheel repair DIY on one of the BMW sites, if you want to tackle it yourself. BUT such fixes are very common and not too expensive and your dealer (who most probably farms such repairs out to some wheel repair depot)would be your best source for accurate numbers. What you might want to do for some degree of raw metal protection until it's fixed is cover the wound with clear paint, after drying it completely with a hair dryer. I've used clear nail polish too.
There's an excellent shop here near Baltimore that does a national business. Shipping costs would have to factored in for that, obviously. I'd be surprised if there's no such resource in the P-burg area. Which leads me to my final point: Whatever the dealer charges you will be the true cost plus his mark-up, so why not just search out there yourself for someone who fixes wheels, and forget the dealer?
There's an excellent shop here near Baltimore that does a national business. Shipping costs would have to factored in for that, obviously. I'd be surprised if there's no such resource in the P-burg area. Which leads me to my final point: Whatever the dealer charges you will be the true cost plus his mark-up, so why not just search out there yourself for someone who fixes wheels, and forget the dealer?