I do all my shopping is tesco and it would be a very rare week that I spent £20 on meat for the 2 of us, often less than £10. I know the fruit and veg stall at our market is cheaper than the supermarket but as I said I'm rarely around when its open. The local butchers I have tried were a lot more expensive for what I buy. I do cook most of my food from scratch but I'm not very adventurous so tend to be buying chicken, mince, bacon etc.
To be fair that £20 feeds five of us !!!!
The problem with supermarket chicken is it has water injected into it ( and sometimes other less savoury things ) to make it look more appealing. We've stopped having a whole roast chicken for Sunday lunch and now, for £3, we get five huge chicken legs with the thighs still attached from the butcher and roast them - stunning flavour and you don't realise the difference until you try it.