Oh dear! My bad, as the kids say. I made a huge boner...er, mistake. And that's something you won't hear the number one PPRuNe fan admit often. So bask in it, lads.
In my above calculations of what a tilt rotor *might* cost to operate, I completely forgot about overhaul reserves. I kind of glossed over them when I was coming up with maintenance costs. Sure, Bell will warranty the components against premature failure, but the operator will still be on the hook for the reserves to be set aside for the rotables.
...Which gets me a-wonderin' just how much all those proprotors, gearboxes, swivel thingees, and those big engines are going to cost to overhaul? Any guesses? Whatever you come up with, just add that number to the $5,400/hour figure. Do I hear $6,000 per hour? BWAAAAHAHAHAHAHAH!
Whew! Sorry. There, I've composed myself now. I'll try not to lose control like that again. And I hope you chaps won't let me get away with such an oversight in the future.
Many thanks.