Like everything else, ammo prices are dramatically up. They've doubled in the last two years.
Some reasons are obvious. Ammunition is heavy and expensive to ship. Transportation costs are up due to high oil prices.
Copper, used to make bullet jackets and brass cartridge cases, is also high due to increased global demand.
Less obvious is the market distortion introduced by the ultimate Big Government program (and that's all it is): War. The Boy Emperor's legions are burning through an incredible amount of the stuff in the Global War For A Legacy: about 5.5 million rounds per month, according to this House Armed Services Committee report.
Thanks, Dubya, and God Bless America!