We probably spend around £100 a week, but haven't been stringent in tracking it recently.
We shop in costco (pepperami, babybel and crisps, for example are much cheaper. And that's before you look at chicken breast and cheese, etc). I also buy their monthly offers. Their 5 litre or so laundry detergent is quite good. They have things like disinfectant, Mr Muscle drain cleaner, and oxy bleach for half the price of other shops. Harpic Black is also cheaper than home bargains, though not by half.
We still eat beef mince but rarely without it being 'cut' with pork mince. I've done it this way for years and my family prefer it, it's just done us a massive favour recently. We're eating more chicken mince as well, as it's cheaper than chicken breast (which is about half the price of beef mince).
I buy meat when it's on offer. Asda had pork loin for £4/kg recently, so I sliced some into pork chops and kept some for roasting.
I'm not loyal to any supermarket. I buy stuff on offer from them all.
My family are a real "no meat = no meal" type bunch. So we have meat with every dinner, but it's bulked up with loads of vegetables. I also buy (dried) chick peas pressure cook them and then add them to curries and different meals.
TL:DR - don't be loyal, shop around. I love costco (though it may not be cheaper if you stop at the cafe every time on the way out!)
Swap meat for cheaper options - pork mince for beef, chicken mince for chicken breast.
Bulk meat with veg or dried beans and pulses.