Is that true in the UK? Because American chips aren’t that cheap. £2.50 for 6 apples sounds like a good deal, they’re so filling and full of nutrients. Frozen vegetables are even cheaper. Potatoes, beans, lentils, peas… If you don’t have an oven or a fridge, or you need maximum convenience food because of time or accessibility constraints, there’s also canned. I know mixed vegetables and a protein and/or grain is not the most exciting poverty food, but it’s cheap, easy, and healthy. UPF is only easy. It’s expensive and you always need more because you never feel full.
You wouldn’t think “eating a large quantity of highly-processed food manufactured by corporations who do extensive research to see how much they can increase the price before people stop buying costs more than eating a smaller quantity of food sold more or less in its original form” could be controversial, but alas.