My local Wal-Mart has ammo relatively cheap, too.
Buying ammo from the WAL-MART here is a lot of trouble. First you have to find an employee, then he goes in search of someone who knows who has the key to the ammo case, then they both go in search of that person who seems to have disappeared off the face of the earth.
Personally, I like the way it was when I was a kid, every country store had a shelf full of the more popular brands and sizes of ammo. You just walked in and got all you could afford or put in an order for what you wanted and it would be there within the week.