Lunch - DD2 - Aldi's halzenut and chocolate spread on white bread, monster munch (from Iceland which is next door to Aldi), apple, Aldi squeezy yoghurt, Aldi fruitshoot, Aldi's version of Jaffa cakes x 3.
Sorry, but I also think that that is a shockingly bad lunch. I can make a packed lunch for each of my DS and DD (who are quite fussy eaters) for £1-£1.30 a day each. This includes fruit juice (diluted with water and packed in a reusable bottle), fruit (small portion of something like grapes, blueberries, satsuma etc) , small packet of raisins maybe then choice of bread sticks and soft cheese/hummus or pitta bread with grated cheese and carrot, or felafels or quorn picnic eggs, and a small piec of home-baking (which normally incorporates some fruit eg a fruit muffin and which I make in batches to freeze). In the winter they often get a flask with some homemade soup (broccoli, lentil broth, tomato and red pepper etc). If you are really short on time or equipment, I admit that the soup or homebaking may not be achievable but the rest is easy to buy and assemble.
I'm sure that some MN people will find fault with this nutritionally but it has a basic mix of protein, vitamins, calcium etc and allows a bit of variety.
For breakfast during the week the kids have organic porridge (made from a muesli base and organic milk) with fruit juice. It costs about 20p tops a serving (including the fruit juice) and takes about 5 minutes to cook (while I am packing their lunch boxes).
Getting back to OP, we eat well and would be hard pushed to spend more than £100-£125 per week for two adults (one of whom is gluten-free and therefore needs more expensive g/f pasta and bread etc) and two hungry children. This includes all breakfasts, lunches, dinners, snacks and household items such as soap powder and dishwasher tablets etc. We are veggie, however, which means that we can eat better quality for less. Apart from the odd jar of pasta or curry sauce, everything else is cooked from scratch, with lots of fresh veggies.
We are not aiming to be frugal but we don't have unlimited funds either. We could probably spend less but we buy organic milk and free range eggs for ethical reason and try to buy organic fruit and veg where there is a choice.
Having said all the above, if people can afford to spend more and want to, I think that is fine. As another PP has said, I don't think that it should be a race to the bottom.