I recently discovered a way to bring my food budget down to practically nothing. I just go to the wild areas around town, and gather up wild plants. Some of them like nettles, are good to eat whole. They're rich in calcium, iron, vitamins C, B1, B2, and many others. They have the highest protein value of almost any plant food - 40% protein by weight when dried.
Others have lots of other vitamins, minerals, antioxidants and such, but are not quite as edible because of bitterness, texture, etc. These can be easily made into an herbal tea, which extracts the vitamins and minerals and puts them into a form that can be easily digested and used by your body.
Today I ate a plate of nettles, and drank a pot of tea brewed with broom flowers, morning glory flowers, red and white clover, alfalfa, plantain, a whole rose flower, and blackberry shoots. I use a coffee maker, and just load up the filter with all of my chosen wild plants, along with some yerba mate for flavour and additional health benefits.
Along with salmon, milk, eggs, and other meats and dairy, occasional storebought fruits and veggies, and carbs when needed, you will look and feel great on this diet.
There are hundreds of plants that can be eaten in nearly every part of the world, and each has unique medicinal and nutritional value. Try it out!