So what has this proven?
You are bloody minded enough to make yourself pretty hungry and miserable for 3 weeks (because it hasn't actually been a month yet!) by spending £35 on snacks and crap...
slow clap
I have had to live on horribly tiny amounts of money.
Between two households (so five adults, 3 in mine, two next door, my best friends at the time)...
We'd buy:
Sack of rice (12kg? ish)
Sack of spuds
Sack of porridge oats
Sack of flour of some sort (often gram)
Cheap bread on discount/whoopsies, to freeze and use slice by slice (so it didn't matter if it was on the verge of going off/stale), two or three loaves
Big tub of cheap spread (then we'd split it into two smaller tubs one per household)
Block of cheese (strong, a luxury, but it meant you could use a lot less)
Box of (nasty caged hen) eggs (15)
End of the day veg off the market - whatever there was, would usually get a couple of carrier bags for £2, stuff that would otherwise have gone in the bin.
Milk
Bag of 30 frozen sausages
Whatever other meat - sometimes a chicken, sometimes next door would get a couple of rabbits for free.
Bacon offcuts
Dry beans/pulses/lentils
We already had a stash of spices.
That would cost us around £30, and last us two or three weeks.
From that we could make big vats of chilli, stew (We called it 'slopdop' a sort of curry/stew thing), and soup, which would be served with rice, baked spud, mash or chips.
Whatever meat would be stripped off the carcass and the frame used for the soup or stock.
We'd use the bread for cheese on toast for lunches, and when that ran out, make chapattis or some sort of flatbread.
Porridge with watered down milk or just water for breakfasts, occasionally overnight oats if there was any interesting/suitable fruit in the market 'end of the day' bags.
Sometimes we would be given free stuff by one persons work place and also occasionally by the corner shop owner - things like bags of sugar that had split or just past use by date jars/packets so we might make cakes if that happened.
It wasn't a lot of fun, but none of us starved. There was zero snacking though!