If you made and airport like Cancun, you don't think it will sell as much as or almost as much as Memphis
Memphis it's just not "any" airport. It's a very important Cargo hub and, it fits with other products we are working too, which are Louisville (UPS Hub), and a Cargo expansion for FSX.
And, it has several new features, never seen before, that required to program entirely new systems from scratch.
It's been almost 2 years without a release now. If these mega airports were being done in one year than I would see your point but they are not. I like mega airports but the development time is long.
Users of a small airfield will expect WAY higher detail compared to a large airport so, it will still take plenty of time to do, but it will still won't sell as much.