A cheap diet can be healthy. Rice, beans, eggs, apples are some of the cheapest items in the store.
Unfortunately, people often try to cook healthy, but they impulse eat unhealthy. Bulk sugar and oil are indeed some of the cheapest foods on the shelf. It does nobody any good to buy them at a substantial markup inside processed foods.
Edit:
What is your 8% source? 12.8% according to the USDA.
Edit: Looks like the AECF link might've been edited as the Google preview said 8% - indeed is 12% on the same link. USDA says 10%: https://www.usda.gov/media/blog/2011/05/03/interactive-web-t...
If dietary fiber is your concern, switch to brown rice and eat some more.
I have no clue what typical vegetable or fruit prices are in the US, but both here and in most Asian cultures known for low obesity rates, fruit is more expensive than alternatives. I don't expect mass produced fruit to break the bank, but realistically it's one of the larger costs.
A $2 bag of apples gives me snacks for a week. A $2 bag of chips gives me snacks for a day.
Why are grocery store websites like this?
Anyway I just got back from the store. I bought: 2 pounds of pears ($3.50), 1 pound of carrots ($0.90), 1 pound of celery ($2.00), 1 pound bag of chips ($3.50)
What does that prove? Not much, except that fruit seems to be in the price range of vegetables, and I wouldn't characterize either of them as expensive. The celery was a bit more expensive than the pears, and the carrots were 50% cheaper. Both fruit and vegetables are cheaper than junk food, so if you can afford junk food you can afford fresh food too.
But not quite as quick as the microwave or McDonald’s.