Why is this so difficult? I'd guess that I average $55 - $65 per week on groceries for the current 4 of us at home now. That's DH (who could stand to lose a few pounds), me, DS4 a HS senior who runs XC and track, and DS5 an 11 yo sprouting up. I also have can impressive stash of basics built up, thus there is overage in my grocery buying.
I was surprised there was no meat, no cheese, no milk, no vegetables, few fruits besides bananas. And not much in the way of treats/desserts (sorry, those are as non-negotiable as protein to me).
Lots of it made sense to me: oatmeal is my go-to breakfast everyday, omelets for lunch at home cheese + leftovers inside) or PB on whole wheat sandwiches at work, but those are both supplemented with soup or stew, and fruit, and cookies, etc. I love pasta and have it often for dinner (but not 4 portions), there's always going to be sauce, meat, veggies, salad, maybe biscuits with butter.