I love when people throw around the "IT's THE LAW" phrase because this gives me a chance to correct them (usually).
Let's say a product is in the wrong place, priced wrong, and a customer chooses to buy the product based solely on that perceived cheaper price. Does the retailer hhve to honor the cheaper proce? NO! It is not the law because an advertisement for something is not a contract.
Most retailers will honor the price however because we know that customers are usually whiny little babies. They will moan and groan until they get their way, spewing logic like "it's the law." It gets quite annoyoing dealing with these people on a daily basis.