Let me throw in the M103 water pump replacement.
I think the flat rate is about 8 hours. I think many techs on this forum said they can do it in 2 hours with a $30 tool (13 mm flex with a long extension).
So why the 8 hour flat rate? Are techs supposed to have the $30 tool?
Labor rate is one thing (I think $100/hr is fair) but over-stated flat rate is another. It is not fair to have over-stated falt rate to compensate for the published labor rate, IMHO.