Walmart has the 50 cent pies and cakes. Watch them for high fructose corn syrup, but many of them do not have it. Pecan, peach, blueberry, are all pretty good.
Good as in "this tastes good and my inner fat kid likes it" or good as in "this is good for me and tastes good and is cheap"?
At my Walmart Kikoman sells miso soup packets with dehydrated seaweed and tofu; just add hot water and you get about 10oz of reasonable miso soup. Comes in a big bag with 3 small packets inside I'm sure would be fantastic on a camping trip. Only about $2.80 for the big bag.
Walmart also has their own branded mac n cheese with the non-powdered cheese, fairly flavorful at I think $2 a box with stuff like bacon cheddar, smoked Havarti, and Italian cheese varieties.
I'm not one to be a health nut, but as I get older I'm finding the "satisfy inner fat kid" foods have to be very rare now.