I am convinced that the economy has a lot to do with fewer sales. The desire to stock up is still there for many, just not the financial means.
I am not comfortable with ammo stock and have maintained my New Years resolution “box a week” average although the urge to buy more is restrained by finances only.
Of course the economy is a factor, as well as the fact that many have horded ammo and simply don't need any more, hence the price drops and availability.