90K service for our 08 RR (primarily the same checklist) is $759.80 at the LR dealer here in SE PA. That includes "regular" dyno Castrol oil and 6% sales tax. I am sure it is based on a set number of hours so pricing may vary simply by the hourly rate charged in different parts of the country.

An independent shop will usually not work off a set number of hours, but just go around and check everything as needed. You'll probably save a small bit of time compared to the dealer and also have a lower hourly rate.

The more you have done in any one service, the greater the differential between the dealer and a good Indy shop. Nothing wrong with either choice, just depends on what is being done, how much you wish to spend, how much you trust your dealer or shop, and what is most convenient.

 

I think that depends on how much the $850 impacts your life. For me, it sounds like a good deal. That is, the few hundred I could save is not worth my time and potential screw-up risk.