Pricing sure varies - this was a free-one-year maintenance due to charity promotion - maint in exchange for 15 cans of food for the homeless. Normally it is $60, but I have seen $69. This is in the Boston suburbs. I have a 3160QDC not a 6600. It costs more to work on a Mercedes!
I talked with the owner this AM and she said it must have been given back by mistake before the tech serviced the machine as there were a bunch of same machines in for service. She said if I bring it back she will do it herself, right away! Can't ask for more than that!
So, it pays to look under the hood when they do the oil change!