Last week when I picked up my M5 the dealer wanted $1800 for the phone. As I perceive it, this is for a StarTac/Motorola phone($250), and a holder. My understanding is that the car is pre-wired for the phone, so I am not sure where the money is going; this seems like excessive markup even by BMW standards.
I talked to Circle BMW in NJ and they said they will sell me the same setup for much less, when they can get the installation kit from BMW, which they said is currently unavailable. A guy on another M5 board told me he got his from Circle for under $850, which is about what I expected to pay in the first place.