You have to be careful with the supermarkets and their 'special offers' I have noticed that they will seel beer for £10.00 a case, then put it up to £22.00 and a few weeks later reduce it to £11.00 on a 'half price' offer.
For meat we tend to go to the local butchers where we can see what we are buying (no prepackaged stuff) and get the fruit and veg from the local market or grocer. It works out a lot cheaper than the supermarkets.