I dunno how eggs are near you (Aldi in minneapolis has them for $2/dozen) but turning a whole loaf at a time of cheap white bread into french toast and sticking it in gallon ziplock bags in the fridge, then if they don't consider it a snack as is instead of syrup just spread jam on it.
French toast is sweet/savory agnostic, you can do all kinds of sandwiches.
Speaking of: https://mstdn.jp/@landley/112248292101028692