There's only 2 of us here (Dad and me) but I thought I'd have a go at listing what we cook/eat and how much it costs... assume a £10 budget for storecupboard ingredients such as red wine vinegar, black pepper etc. plus another £10 for veg and fresh herbs
1 large Tesco chicken - £4
Roasting it today with:
New potatoes (£1.80 per 2.5 kg)
Paxo sage and onion stuffing (£1 for 170g)
Fresh green beans (£1 for 220g) - will use half
Fresh tarragon (80p)
Tomorrow it's Bratwurst (£1.79 for 6)
German potato salad, using some of the aforementioned spuds, red wine vinegar from the storecupboard.
Smoked streaky bacon rashers (£2.70) - will use half of them
Remaining green beans
Thursday - cold chicken salad using the legs and thighs from today's chicken, storecupboard mayo, 1 little gem lettuce from a pack of 4 (£1.50 for the 4) and tomatoes (£2 for 5, will use 2)
Friday - luxury night!
2 Tescos Finest fillet steaks (£13.60!)
Mushrooms (£1.25 for 'finest' forestiere)
Double cream (£1.10 for 300ml, will use half)
Parmesan (£2.00 for 100g, will use half)
Little gem lettuce (from the 4 pack)
Saturday
2 boneless salmon steaks (£4.00)
Watercress (£1.25)
Cream (leftover from Friday)
The last lettuce!
Sunday we'll probably go to the pub for a roast.
Dad has cereal for breakfast every day (£2.09 for 500g Kellogs + milk from the milkman)
I have a couple of duck eggs (£2.50 for 6) and either bacon (600g for £4, lasts 4 days), or Indian spiced (using spices from storecupboard) with tomatoes - if there are any left, or scrambled with smoked salmon (200g, lasts 4 days, for £5).
We don't do lunch, and I'm low carbing, so Dad gets the carb options, I pile on the veg and/or salad. I'll make chicken stock from the chicken carcass and any tired looking leftover veg - will freeze it for future use.
I consider our way of eating to be somewhat luxurious and indulgent, but it's not overwhelmingly expensive when you add it up.
Back home with my husband we eat a bit more frugally - lots of mince and eggs, and he loves pasta, which is cheap - I just put lettuce under my bolognese or carbonara sauce. I make a lot of curries too, and am a bit anal about them so have a huge collection of spices which doesn't need topping up that often.
So there ya go - if I had kids I might struggle!