Only in terms of time, at least here in Europe. If you get noodles, flour, rice and in-season vegetables and fruit (and don't choose these for wants but for price, there are some ridiculous deals sometimes), plus some more expensive ingredients such as eggs and milk sparingly, it is very cheap. There's no way processed food can beat that.
See, you are assuming that noodles, flour, rice are healthy for you.
There is good evidence that in fact, it is not. Many of those things are inflammatory. Also, following advice they get from doctors, they are using more and more poly-unsaturated fats. Which as we are discovering are actually substantially LESS healthy for you than saturated fat!
And in terms of time, you are ignoring the only thing people have a fixed amount of. By ignoring that, you're ignoring a very important factor that causes people in to bad eating choices. Not that they even know what good vs bad are (as I hinted above, so-called 'healthy' food for you isn't!)
Well, you can also get lentils, whole-grain bread/noodles/rice/flour, chickpeas and other things as cheap staples (if one leaves the meat out as in my example it's not even optional), but I guess that's not what you mean? What would be your suggestion as staple?
There's a problem with nutrition research in that it changes recommendations every once in a while. The only constant seems to be 'Eat food, mix it up - naturally colourful things are good, don't eat too much of it', so I'm going with that for now.
Concerning time.. it's maybe more of a knowledge and organisation thing, which takes time to aquire. Unless you want really fancy food like sushi.
Food doesn't jump into kids' mouths and eat itself. If there's a problem with what kids are eating then it's their parents who are to blame.