Not sure what you mean low budget but I've done MANY low budget trips.
Regarding meals-this is what we have done
We bring breakfast from home. Boxes of cereal, bagels, cereal bars and usually fruit.
We ALWAYS pack a lunch-sandwiches and fruit, juice boxes and splurge on mickey bars for dessert
We bring a crock pot, crock pot liners (no clean up, just throw away the liner) and make a few meals in the crock pot. We prepare items for the crock pot in advance and then freeze the ingredients and put them in the special bags and remove the air with our little machine we purchased at
walmart.
We pack the cooler with the items for our crock pot meals and with lunch meat, mayo, etc. When we get to our hotel we buy milk
Usually we have a suitcase with just our snacks and food, bread, etc and we check the cooler. We don't put ice in it because we freeze the ingredients for our crock pot and we freeze 2-2 liter soda bottles with water to keep them cold. Then we just add ice every day
This has saved us hundred of dollars or more! That way we can pick some special places to dine for sit down! We always go back to the hotel for the afternoon for rest/swimming and just eat our crock pot dinner after a swim!