Yes, yes there are foods that are cheap, delicious and healthy. Sorry this will be a long post, many things to cover!
First I have to say, what I regard as healthy for me personally is generally Keto friendly foods. This is because, for an unknown, diagnosed (not for the lack of trying) reason I have muscle and joint pains that go away if I get to a very low carb intake such that it has an anti-inflammatory effect. Other than working around the reason I have pain, it also remove redness of Seborrheic dermatitis which I have. For me it also reduces quite a bit, but not stops dandruff. It has other health benifits as well, it is not a cure all, I've never said it has cured any of the symptoms above, just reduce or remove the symptoms. For me the symptoms come back when I eat carbs, even if I stay away from sugar. Well it can cure some things like fatty liver or insulin insensitivity. But its not a cure all, again my symptoms (except I was insulin sensitive which is cured) are not cured, but it does work in a palliative manner.
Keto doesn't work for everyone. Well if losing weight is a goal, and then you actually do a keto diet, it will work. People who say it doesn't work for losing weight are either knowingly (lying to them selves) or more often unknowingly eating carbs they don't count. Also by count I don't mean actually keeping track of, because literally counting carbs, nope, I don't believe in that. Too much work, and doesn't give a benefit over adhering to just what ingredients you can use.
What I actually meant for keto doesn't work for everyone, I mean work as in being healthy. It should work for the vast majority of people. But example my wife, she has Ulcerative Colitis, pre-diabetes, and she is underweight. Ulcerative Colitis in regards to keto mainly makes it so certain types of fiber is not good for her. And being slightly medically underweight, she can't eat enough, she needs the carbs. For Diabetes type 2 keto diet is super effective at palliative helping, especially if it's just pre-diabetes. But alas, she can't hit her calorie needs without carbs.
Before talking about the foods, I wan't to mention that Keto diet goes very well together with intermittent fasting. This is mainly due to how the liver works. Making ketons! Keton's isn't mumbo jumbo, simplified its what your liver makes when breaking down fat. Ketons is a very good fuel source for your body. If break down fat, you get much more energy than if eat carbs. So you want to stay in ketosis for more of the 24 hour day, than is easy without intermittent fasting. Ketosis is just when you produce ketons. So to get there, very grossly simplified, fast, don't eat carbs or eat very low amounts, and eat lots of healthy fats. Again grossly simplified, eat almost any fats, but not trans-satiated fats, those are poison to you anyway. When it comes to proteins, I just try to eat lots, and if I get a tummy ache due to eating too much proteins, then I eat less proteins. I don't worry so much about eating enough proteins if I don't workout. I lied above, by omission. I eat lots of carbs, because there are some carbs I don't count. By count I mean I don't regard them as being calories. What calories do I not count then? Mostly vegetables! Some veggies I do count though, like potatoes.
I need to have a short paragraph about eating fats. Its super important in a keto diet. Fat makes you feel satiated. It is no surprise since fats are much more energy dense than carbs including sugar. Feeling satiated is hormonal. Your body does send out hormones, or inhibit hormones, and Ghrelin hormone makes you feel hungry, and Ghrelin production is suppressed when you are digesting fats. Terms to google in regards to this is "fat adapted" which means that the body can more easily use fat as a fuel source throughout the day. And "insulin resistance", not directly related, but very important.
One more thing, when cutting out sweets, everything else starts tasting much better. Everything that has a hint of sweetness gets amplified. Even cold brew coffee. I often cold brew at home, and then heat it (pour some concentrated cold brew in a cup and add hot water), and its so sweet I almost dream about it.
Lastly, and shortly. What supplements do I recommend? Generally assuming you don't have any deficits due to your diet. If I want to eat as much protein as I can tolerate (like because of working out) then whey protein, without added sugar is great! Creatine is also great I could write 3 paragraphs about creatine, and lastly(assuming you get enough vitamins, minerals, and omega3) I also recommend, psyllium husk. Psyllium husk is a great source of amazing fiber, and it really helps me stabilize my gut. Especially together with a keto diet, I go from having close to IBS to feeling like I got a very healthy gut.
Next the foods: I'll reply to my own comment because there is a character limit