TNUC, you have just summarised this whole thread. It should just be done, or scrap the whole aircraft.
Like you I have seen some shockers, and in some cases the owner can not afford to keep the aircraft flying, or has short arms and deep pockets.
They will also not blink at $140 per hour to service the Merc or BMW, yet tell you that $100ph for the Cessna is extortion.
I am retired now and only just do small contracts.