Work on a good day for the engines,3-4 for the airframe, hrly rate of say $70/80, filters parts, AD/sb checks/cables/torque tube/landing gear/compass swing IFR checks. Comanche's are buttoned up pretty well....the airframe inspection can be a lengthy period, there are more screws than Kings Cross! The best way to understand is to work on your aircraft under supervision of your guy and see whats involved. As far as engines go....bullet proof!
There are only two guys I would let go anywhere near my birds with a spanner, one is at Murwullumbah (sic?) and the other is at YKMP. Let me know if I can help.