With main dealers now charging anything up to £75+VAT per hour for labour the costs soon mount up. Mind you, a lot of the jobs can't be done in the time allocated by the managers or manufacturers so the costs mount up even more!!!!! Just remember the nice comfy seat and the cup of coffee you had from the machine while waiting for your car - and the quick cleaning of the car, these things don't come cheap.
0.3 hour (18 minutes) may not seem much time for a 12,500 mile service but it is only a quick check of brakes and lights and oil and filter change (you get a new filter if you are lucky, as my mechanic mate says, it's down to the mechanic who inspects the filter if it gets replaced or not, OK for an air or pollen filter, but how the hell do you 'inspect' an oil filter?).