If the price of an item was changed after I pull it off the shelf I’m telling the cashier to take the item out of my order, and the company can deal with the logistics of restocking the item. For future shopping trips I’m using my smartphone to snap a picture of every price tag as I’m putting an item in my cart. Failure to honor the price on the tag when I pulled it off the shelf is met with me walking the fuck out of the store with nothing. Now you can cancel the order and restock a whole cart of groceries. Let’s see how many man hours of labor you save then.