I purchased a HEXCODE GS-911 and the service manual and so can/will do all factory services myself. I can also reset or change any settings that a BMW shop can do.
This is the key. It's a whopping investment, but will pay for itself over time.
On my RT the oil change is easier than it was on my ST, the oil filter is recessed in the oil pan under the bike and accessed without removing any plastic, on a GS you would have to remove a skid plate.
+1.
Overall, maintenance on the BMW has proven to be simpler, quicker and easier than it was on my ST.
That said, the OP is correct. Shop maintenance is spendy for the BMW. Then again, I always felt that shop maintenance on the ST was spendy too.
The economy of it with my BMW purchase was as follows: The BMW was a couple thousand cheaper than the ST1300 out the door.
By the time I added the farkles to the ST1300 to bring it up to the package of the BMW, the ST cost more still.
So, the BMW was cheaper.
That said, the maintenance costs are higher, and in my own case, BMW limits the RPMs via computer until I comply with their mandated warranty checks. My first oil change was $230.
Over time, the cost of the BMW will reach the cost of the ST1300, I'm sure.