I have one new OEM virgin key fob for sale. It comes with a blank emergency blade as well. I bought 2, but only ended up using one. It is virgin, so with a right tool, you can program it to your CAS and initialize with your car. You will need a key programmer to get it done. BMW dealer cannot program this key, look around for a Locksmith that works on BMW first, and it will cost around $100 to get it done. With a right tool, it'll probably be a few mins if you have a working key.
A normal replacement at the dealer will cost about $280-300 for the fob and the blade is another $70. So about $370, and that is if you can initialize it yourself. I've told that dealer charges another $180 to initialize and disable lost key. $170 vs $370
I can guide you in the right direction and how these keys work (all the details about these BMW keys, etc..), just PM me with questions. But I cannot add the key or reprogram it for you.
It is for 2004 - 2013 BMW 3 Series and 5 Series with Comfort access.
IC: 2671-5WK49147