9bit,
The problem really is that Sims don't come cheap (50-100 million for a new pair of full motion level D's I'd suggest) and capital investment up front is not something MOD are fond of. Given that the cost of an Antonov to ship your aircraft to the desert is a million quid, you can run a good few years of exercise for the price of a new sim. Even with the latest visuals in the front end, that still doesn't cover the cabin, which is a whole other level of technology to simulate, again, not impossible, but not exactly super cheap!