I don't buy all my food from big supermarkets like Tesco's, Asda etc. I go to Iceland or Farmfoods as a lot of the branded stuff there is significantly cheaper. If I do go to a big supermarket I usually go for the offers, two for the price of one etc, sample the cheap value range of foods, hit & miss but some of it is as good as well known brands or I get stuff there I can't get no place else. Best to shop around if you want to save money.