It’s a marketing ploy on the part of Walmart so they can herald the fact that they roll back prices. Of course, the items they roll back prices on are not the stuff consumers will get out of their way to realize the savings. They use those roll back priced items to lure consumers into the store and once there, they know that the impulse-buying trait that most people have will raise their margins ahead of the loss from the price leader items they advertise.