I think you need to have the first service (600) miles, logged into BMWs computer, to not void the warranty. $850 seems crazy, gouging....but this is part and parcel to the brand. It's like buying a Patek Phillipe watch. In theory it's the top of the food chain and you are expecting to pay to be part of the "club". Obviously you'll stay to hell out of there if you can in the future. Probably the best way to look at it is....it's nice that you can afford the bike in the first place, and are in good enough shape to ride it. MANY that can afford to buy a dealership are physically unable to even consider riding a motorcycle....they can barely walk....
I had a cigarette type offshore boat......Brand new, but I had to keep upping the power until the boat was unreliable. When it ran, it was heaven on earth. But that was rare....if I break down the expense....it was ridiculous....instant divorce if my wife ever found out what I was spending....and mind numbing disappointment every other time I took it out....
So a BMW bike....cheap in this life...
Enjoy the ride....it goes quick.....