In fact it isn’t cheaper to eat highly processed food: a typical order for a family of four -- for example, two Big Macs, a cheeseburger, six chicken McNuggets, two medium and two small fries, and two medium and two small sodas -- costs, at the McDonald’s a hundred steps from where I write, about $28. (Judicious ordering of “Happy Meals” can reduce that to about $23 -- and you get a few apple slices in addition to the fries!)
In general, despite extensive government subsidies, hyperprocessed food remains more expensive than food cooked at home. You can serve a roasted chicken with vegetables along with a simple salad and milk for about $14, and feed four or even six people. If that’s too much money, substitute a meal of rice and canned beans with bacon, green peppers and onions; it’s easily enough for four people and costs about $9.
By the way, note the phrase "despite extensive government subsidies." It's almost as if the government doesn't know what's best for you. Via Is Junk Food Really Cheaper? - NYTimes.com.