Personally, I've dropped Wally world as a place to purchase ammo. I'm also trying to wean myself off buying anything there... difficult to do, but I'm working on it.
For one or two box quantities, Academy Sports, hands down. For larger purchases, TargetSports USA, or several other online places, CDNN, Natchez, etc... depending on sales...
Also, don't write off the brick and mortar gun shops. I've been surprised at how close some of the ammo prices are at my local gun shop.