^^^ this X 100,000,000,000,000.99
There's a lot of well-documented reasons why the Military and all but 3 or 4 LE agencies in the U.S. are running as fast as they can from the 9mm. And some are even starting to realize the .40 was going from bad to worse in some cases. Everyone ends up coming full-circle back to the old .45.
As for ammo costs- where on earth are you folks purchasing your ammo from, that 9mm costs much more than $2 or $3 bucks different from .45 ? If even that much? Most stores I've been in-from mom-n-pop local gun shops to Gander to Dicks to Academy- there's almost zero difference in price from .40-9mm-.45-10mm all the way up to .50AE on the shelves. Some spikes for .41 Mag/.44 mag and .454 maybe but,...
Just using one of your examples (Gander Mountain), we can see that there is a significant price difference between 9mm, 40 S&W, and 45 Auto. Look here and here. I'm not sure where you're buying your ammo, but it's not at the level that you claim it is.