We use MB warrantee Flat-rate time for basic calculation of charges. Experience will sometimes modify this time if it is a proven problem to to the job in that time due to conditions that accumulate on older vehicles, such as rust.
There are many fine general shops that feel their skills are worth paying for while they learn on different systems each day. For many customers what they loose on the complicated issues they are willing to pay for to have an honest attempt by a competent tradesman for all their vehicles. I assist many quality techs deal with their once a year MB.
I believe there to be an ideal value for each job. That would change from one area to another because of different costs, regulations, etc. But, it wouldn't change from tech to tech under similar economic conditions. I would really hate to pay for car repairs with California dollars. But I would gladly work for those dollars.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician