They have to know their days are numbered, so I'm sure they're trying to squeeze out every last penny for their pockets

In the US, at least, school might be the only time they're getting meals. Many children qualify for free breakfasts and lunch. Food is expensive. Mom or dad might be working multiple jobs to stay afloat and don't have time to cook, or might not know how. They might live in a food desert without access to a real grocery store, and all that's around is a convenience store or gas station.