YANBU. In fact I think I spend more.
I feed six, five of whom eat like adults. I've kept the same budget for years at £600 per month for food which is about £3 per person per day, for breakfasts, weekend lunches, dinners, drinks, snacks drinks and booze. We use 35 pints of milk a week, and about 20 eggs.
This has felt tighter as they have grown into hungry teens, but by cutting meat, increasing veg and not buying many processed foods I find we can still eat well. I bake and do my own bread, pizza, soups, yoghurt.
We find buying large joints or whole chickens is the most cost effective way of having meat, the leftovers going to make cottage pie or curry, or as a pizza topping etc. We have meals with little or no meat like veg/lentil soup or pizza, of curries with chickpeas. Salad can be grated cabbage and carrots with a vinaigrette, or spinach rather than an expensive bagged salad, of which we'd need two.
I would never buy chops, or chicken thighs, haven't bought chicken breast for years or fresh fish. all are too expensive. I use a lot of frozen fish though.
I do a fajita thing where I fry up onion, peppers, with seasonings and add left over pork or chicken, then put it in a wrap.
Threads like this are useful to pick up tips 