I personally know some folks who spend all their money on fast food, and then online it seems pretty common folks not knowing how to cook causes massive financial problems.
My super duper cheap meal that takes no effort is “lazy rice veggie soup”: Can of peas and carrots cooked with a bouyon cube until cube is dissolved Add cooked rice to mix, and heat until rice is flavorful with absorbed broth
I do a cup of dried rice, and a can of peas and carrots which means the soup has 800ish calories and I think it’s pretty good as it’s either 2 small meals that you can have sides with, or one large one!
So what are your cheap meals you like to make? The less well known, the better!
Eggs, bread, cheese and Mayo or ketchup. I could eat egg and cheese sandwiches 7 days a week if I had to. Aldis eggs are usually around $1-2 for a dozen, bread is about a dollar. The big pack of aldis brand cheese is about $2 for 16 slices. Not counting sauces since you don’t have to buy those often
16 cents per egg Estimating 10 cents a slice but probably less 12 cents per slice of cheese About 38 cents per sandwich
Then throw in some various fruit and vegetables
Banana, cucumbers, snap peas are cheap
Edit: you said not common. Sorry lol