I have another dealer alternative... United Auto Security. I used them for my M3 alarm, but their locksmith service is excellent too. They have full EWS support.

For my 2003 X5, I just recently purchased two extra Master Keys for $198 including Overnight shipping both ways. I mail them my key and the EWS module, and they do their thing and send it all back. Takes about three days from start to finish. I plugged in my EWS and the car started right away. About 3-5 minutes later I had programmed both keys for my factory alarm and keyless. Full factory functions again.

I was weary of the dealer option as I wasn't 100% positive that the previous owners hadn't swapped lock cylinders, so I felt I needed to find an alternative that replicated my existing (and only) key. I'm glad I did.

It's worth noting that I received OEM BMW key blades and housings. The key guts were aftermarket but it works great. And my M3 system has been going strong for several years now. Hope this helps somebody.