the MOD don't do complex, technical explanations - not only do half the MOD press team know no more about such things than i know about brain surgery or speaking Esperanto, but they know that even if the 'defence' correspondants in the media understood it (they usually don't), such detailed stuff would never get passed the editors desk - it doesn't have big tits, or a weepy back-story, or have 'celebrity' in the title. and thats just the Broadsheets..
yes, war costs, but most of the expendible stuff is just part of a pre-programmed cycle of expenditure - the big cost of wars is expansion of force: employing more people, buying lots more high value stuff.. this will see larger numbers of Enhanced Paveway IV bombs and Brimstone missiles being bought to replace stocks used, but it won't see more crews being recruited or aircraft being bought - and even then the headline figures (£40k for an EPaveway IV, £65k for a Brimstone) are misleading - the MOD pays 20% VAT on everything it buys, the companies involved pay corporation tax, their employees pay income tax and NI etc...
in terms of wear and tear its not really an issue - the aircraft will be bought/designed with a certain number of flying hours, take-offs/landings, and a 'fatigue index' in mind, and that will be worked out with a peacetime/wartime mix factored in to it. sometimes of course circumstances mean that the mix doesn't happen - the perfect example being the RAF's C-130 Hercules cargo aircraft: Iraq and Afghanistan have run through the flying hours, take off cycles, rough feild operations and harsh manouvering calculations like a dose of the shits - so much so that the'll be retired 10 years earlier than originally planned because they'll be utterly shagged.
actually, for the Tornado's, the wartime flying is less harsh than peacetime flying - in the UK they bomb around at 200ft bending trees nd scratching rocks, in Iraq they'll tootle up to 20,000ft, fly nice easy patterns and generally have a fairly relaxing time...