[derekgas]

Asda, Tesco, etc, dont have to buy stuff (including petrol) in the way that smaller retailers do, they dont ask the manufacturers of say baked beans 'how much will it cost for a million tins', they would TELL the manufacturer, 'we want a million tins of baked beans, and will pay you x amount', same with the petrol stations! It is then up to the supplier how they cover some of the losses, hence things like mars bars are smaller, because the manufacturers have to keep the big companies happy. B & Q, Comet, Curries, British Gas, etc etc, are all the same, they buy for half the price that small retailers do, but most are still expensive in comparison.