I know of people spending £30-50k per annum.
Jason,
I think once you get away from the maintenance outfits that mainly deal in Piston equipment, to those who mainly work on Turbine kit you will find a big difference in responsiveness. We can send a Citation in for a heavy check, say a 600 hour check or a phase1-5, and it can be back in service in a week or less. Annuals on SEP's, which are trivial in comparison really, routinely take several weeks.
Good inspections are essential, as you mentioned. I once went to South Africa with an engineer to pre buy a Kingair 200 and the borescope found cracks on one of the rings within a couple of hours of our arrival. It was a 6 figure repair and as it happens the owner didn't want to to cooperate so we came home.
We had P&W do a full boroscope on our engine even though it had only 200 hours.
