When I went to the lunchroom in high school, it was required to pay up front in cash ... I usually couldn’t afford it ...
The ‘lunchroom’ I had in high school consisted of a space with bleachers & ONE cooler that held milk cartons=
8 OZ for 5 cents. We packed our own lunches. A whole loaf of Wonder bread was used every day for PB & J sandwiches for all 4 of us kids. Maybe an apple or a banana.