I will add this:
Beans and frozen vegetables are your friends. Get a crock pot. Make a crock of beans, divide them into servings and freeze them to use as needed. Beans are good nutrition. Meat and bean dishes go much further than just meat. A crock pot is also great for turning less expensive cuts of meat into a feast.
I find that frozen vegetables are much handier than canned, they keep nicely, and don't have all the added salt or other ingredients. Having them in the freezer makes adding vegetables to a dish, or making a side dish, very easy. You can easily have several different types or mixes to use as desired. Spinach in the omelet, mixed veggies in the stew, and so on. Getting those vegetables into your diet is better than just going for a burger and fries all the time.
Eggs are a great source of cheap protein, and sometimes they even go on sale. You can hard boil them to keep them longer.
Keep an eye out for sales on various fruits and vegetables, such as apples, sweet potatoes, or potatoes, and buy a bunch.
Frozen bread dough can be quite a bit cheaper than already baked loaves. Having some in the freezer during bad weather means you can have bread in case there is a run on the store (as sometimes happens) and the shelves are bare.
Raman can be tasty, filing, and tempting, but you might want to leave it as an occasional treat with all the fat and salt in the standard cheap stuff. Nutritionally you're probably better off with a potato.
You'll know you're developing the right mindset if you look at the price of a standard fast food "meal deal" and think to yourself: "I could buy a pound/half kilo of hamburger, a loaf of bread, and add a few pennies of potatoes and eat for 3-4 days for that! If I made a meat and bean stew it would be all week!"
Plan ahead. If you are going out, bring a container of water and a snack, such as an apple. That way you can avoid the temptation of soda and a candy bar. It's cheaper and better for you.
If you do it right, eating fairly cheaply can be healthy too.