We have one Nepali shop here nearby. They prepare very low cost momos. It is one good food when you are low on cash. I also prefer to eat the fried rice. It can be good option during the weekend. I think even the chinese food which is low cost can be good enough for the weekday. I only eat the non veg during the weekend.
My go to cheap food was buying the Ramen noodles in the packet, I admit it isn't a very healthy food choice because of the chemicals that are infused in it and because it reportedly takes two hours to digest. I wouldn't recommend eating it often, I don't for sure, but it's cheap, it's tasty especially if you add seasonings in it and it can full you for a few hours. Bread and some butter or cheese would help me as well on a budget, even crackers. I always recommend buying a fruit or some veggies, it's not too much if you buy them separately and it's an alternative healthy choice of budget food.
If I am really low on cash I usually turn to ramen noodles, tv dinners, bread, and occasionally fruit if I get the chance. Mainly oranges and bananas and sometimes applesauce every now and again. I might occasionally buy cheese and ham to make a sandwich.
We buy good in bulk once a month. This helps in so many ways as you are to save money and also you will not have the issue of not having food at home when hard times hit. What I also like to do is to freeze cooked foods. I make things like cut vegetables, meat, chicken and turkey. I precook and freeze them. Food should always be a number one priority. You may not have clothes or entertainment, but you should always have food.