Henu has good advice. At least where I live, it is amazing how much money can be saved with just buying different food. And the food that is cheapest is also healthiest.
All of the premade and packaged products are expensive, and these are the things that are usually not healthy. But I can buy a big bag of like a gallon or 4 liters of jalapeno peppers for like only $3. And a big bag of onions for $5. You can get a 20 pound 10kg bag of dried rice for like $15 that will last a very long time. It's amazing to see how much money it costs to buy only a few things that are packaged or premade, and what a large amount of food you can get for little money if you buy the ingredients and make it yourself.
Look at cuts of meat that are less common or are often thought to be not as good. You can find these on sale for very cheap because people don't want it, and you can find recipe videos on youtube showing how to cook it in the correct way for it to come out just as good as any other kind of meat. Like a piece that is hard, there is a way to cook it that it will come out just as soft as anything else. My favorite cooking channel is Glen and Friends Cooking.