Greed, fear. EOW/ELE/SHTF folks, some people getting ready for 12-21-2012 (some kind of space planet Myan prediction) and I feel (no facts) that many of the ammo mfg actually cut production of ammo and components to keep the prices up.
My Walmart in Sandusky (route 250) is full stocked of ammo, not much you cannot get there right now and at decent prices. They even have a decent reloading section with primers, bullets and powder. They have a great .22 rimfire display of CCI/Win/Rem.
At Walmart. there were case supplies of .308, .223, .45, 9mm, 38spl and 12 ga skeet.trap loads. 3 full 7 shelf shelves as end caps to isles with all kinds of different shotgun ammo.
They even had oddball Mil-surp calibers in commercial packaging.
The two gun shops near me never did carry much ammo due to walmart and gander mountain right down the highway from me. I have not checked Gander prices but they do have ammo for sure. The range I shoot at keeps a very good supply of ammo and reloading stuff. They even give reloading lessons once a week to new and experienced reloaders.
Most of any ammo, reloading stuff I will ever need came from my brother in Cleveland when he owned a gun shop. It will be a long long time before I need anything unless it is impulse.