Wiz and Cunning,
I didn't include lease costs because they are a fixed cost - yes they are amortised over the annual utilisation in order to determine an hourly rate for the machine, but in reality you pay the rent regardless of how many hours you fly.
The lease rates vary depending upon a number of factors and when you took the lease - lease rates on Sept 12, 2001 were very favourable!
With regards the extraction of another sector I agree, however on a day to day basis it also isn't a consideration - the operations people don't sit there and say "oh goody VH-XYZ is getting in early - lets bung on another SYD-BNE flight"
The reality is that going fast may well be a viable commercial policy which trades fuel costs for extra productivity out of the machine, but these are longer term strategic decisions.
By shaving a minute or two off a sector at a cost of 100 or 200 kg we are costing the company money - money which they will seek to get back by not offering us a pay rise come EBA! (the buggers!)
Finally the age of the aircraft doesn't necessarily impact on the hourly operating cost.
My components these days are on "power by the hour" deals where a fixed hourly rate for the component - engines, apu's landing gears etc is paid and the supplier undertakes to provide a servicable component. If it karks it, a new one is wheeled in to replace it at no cost (apart from opportunity cost, lost revenue due not flying etc)
It is all very involved these days and the old theories of faster is cheaper have been superceded.