Not sure if it is true, but a sales person at my local Autozone said the reason for the sales on oil, is they are clearing out old stock, getting ready for Dexos labeled oil.
I picked up 3, 5 quart jugs of Castrol GTX for $5 each. My son, who works at an Autozone in Kentucky said they cleared out Penzoil Ultra at $1/qt. Sure would be nice to get a piece of that action.