I do one bulk shop per month for the big ticket items such as washing powder, tinned goods, clingfilm etc.
That is done online so that i don't "browse"
I then bulk buy dry goods such as pulses, oats, flour from my local asian shop. I pay around £2.50 for a sack of rice that will last us just over two months. (2 adults and 2 kids)
I use a local butcher when i can, meat isn't any cheaper but it tends toi be a better quality and i bulk out meals with lots of veg etc.
Also things like a chicken will make several meals. Risotto, roast, pie etc.
A lamb shoulder joint would do 1 roast, 1 shepherds pie or rissoles.
Milk and bread i buy from the supermarket.
Veg i buy from the local outdoor market, it's cheaper and tends to be better quality. Also i meal plan so don't over buy if you see what i mean.
IE, as i buy from the market i don't buy packets of carrots, i just buy however many i need for that particular week.
I also grow some veg in pots in the garden. All our salad came from the garden this year.