Surely people living on a tight-budget would do better to buy stuff in bulk, not just on a week-by-week basis?
Bulk goods are certainly cheaper — but buying in bulk assumes an initial availability of cash which wouldn’t necessarily be reflected in practice for those in poverty. If I was sticking to this budget for a long period, bulk goods would certainly play into it more. However, I wanted to see how much variety I could achieve in a single week, which buying massive quantities of a single item rather works against.