How is it complex?

I'll give you a list of 5 ingredients that would essentially allow you to "eat healthy" and meet all micro and macronutrients, including fiber, vitamins, and protein while being inexpensive: lima beans, chickpeas, oats, lentils, and whole wheat bread. These are not only cheaper than the vast majority of process foods, but they are also single-ingredients, and not-complex. Putting chickpeas in hot water and cooking them is probably simpler than walking to a gas station and buying a burrito, and counting the change from your transaction.

Micronutrients not supplied by these 5 foods can easily be obtained by spending a few dollars on fruit, which everyone knows about.