Another example of careless shopping costing consumers their cash was recently given by Asda on its sale of Cathedral City cheddar cheese and reported on the Watchdog TV programme.

A 350 gm piece was offered at a promotional price of £2, whereas an “economy” multipack of two 350 gm pieces was priced at £7.29, or £3.29 more than buying two single packs. So the unwary, those who trustingly believe bigger packs always offer better value, those bad or slow at maths or those in a hurry to do the shopping and get home were giving Asda more than 80% more than they needed to.