TC - your obviously not in the accounts department!
Cost of operating the aircraft
(Fixed Costs + DOC/hr) / Number of hours flown.
Normally fixed costs are:
Insurance
Cost of the cash (whether yours, taxpayers or whoever)
Crew - possibly the largest cost.
Direct Costs:
Fuel
Oil
Maintenance - which could be fixed in some cases
Overhaul reserves - whichever way it's worked.
I would be surprised that your operations are not on PBH on both the airframe and engines.
To increase the efficiency in anyones mind as you posted yourself is to fly more hours. The Americans by your own statement get 3.6 times for the same amount of money!
What Shawn Coyle was probably alluding to was that an extra aircraft only costs insurance and cash servicing.
Somebody refferred here that UK police operators only fly on average 3.5 hours a day. What do you do the rest of the time? Under Part 91 there are no flight or duty time restrictions. In fact some of these operations could be under Part nothing at all!