An educated guess would be about £90 per week, however, it's often more and often less!
We buy fresh meat and fish from the wholesalers, and home freeze it. If we do a 'big' wholesale order, it can leave us with a £500 bill, but fills the freezer up.
Rice, pasta and bread flour (make my own bread most days) are also from the wholesalers.
Veg is almost always from the local farm shop, and averages about £12 a week. Eggs are from my friend Jude, organic, free range, huge and £2-00 a dozen!
Laundry liquid, loo rolls and cleaning products are from the nearest factory shop.
On the three days a week when we childmind DGS, at our house, he has breakfast, lunch and dinner, and unlimited fruit, as he has hollow legs! Those days the bill is much higher than for just the two of us. He's not even two and a half yet, I hate to think how much it'll take to fill him when he's a teenager!
If I have a batch cooking/baking session I always send half of everything to DS and DDiL, they both work full time in high powered jobs, and often carry on working at home until late at night, (after devoting evening to DGS), so they have a few home made ready meals in their freezer.
I never, ever waste any food though, never even roast a chicken without using the carcass for soup. If lettuce gets a bit 'past it' it's wilted down or dry fried until crisp and served as a topping for veg. We quite frequently have what DS has always described as 'random casserole', if it's in the fridge and needs using, it goes into the pot!
We're not teetotal, but we're not far off, so our alcohol spend is negligible. We have a very healthy 'booze' cupboard, as most of our friends don't drink much either, but it's there for visitors, just in case!