Seeing price on the shelf but paying a much higher price at the checkout. Other supermarkets are guilty of this but ASDA is very bad. ASDA must profit millions of pounds from this. Most people don't bother querying this at checkout as it only amounts to a couple of pounds and not worth the bother of delay while assistant goes to check the price. Strangely it never happens the opposite way where you are charged less than the displayed price.