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 entire order and restock a whole cart of groceries. Let’s see how many man hours of labor you save then.