Had a friend in college who would sneak into an All-You-Can-Eat buffet restaurant through the kitchen (former dishwasher who had some friends there) and carry off boxes of food at the end of every night. He claimed that his food costs were under $.15/day, with most of that just going to dishwasher detergent.

Significantly healthier than the All-Ramen diet and cheaper even than the dorm cafeteria which typically clocked in at around $2-3/day.

He saved up about $2000 by the end of the year as a result and - being the savvy investor that he was - bet it all on LUNA coin. I got to hear this as I was in his dorm room to talk him out of killing himself.