Instant Noodles
Instant noodles, such as ramen noodles are lightweight, cheap and easy to prepare. A bag costs a fraction of a dollar and can be a whole meal in a survival situation. The classic macaroni and cheese is also an extremely inexpensive survival food. It can be made with nothing but the ingredients included and water if necessary.
Staples
Staple grains are cheap and filling. Beans and brown rice are two choices that are filling, cheap in bulk and that provide complex carbohydrates. They can also be used to stretch other foods, such as stew, out to provide a full family meal from a single can. Ground oats are also quite nourishing and inexpensive, as are lentils, quinoa and other grains.
Baking Supplies
Just because you are going into a survival situation on a budget doesn't mean you need to go without baked goods. Flour, sugar, salt, oil, shortening, baking powder and baking soda are cheap ingredients with long storage life. Add powdered milk and butter and you can bake many foods.
Discount Canned and Bottled Food
No survival kit is complete without some basic canned nourishment, but the price of canned food can add up. One way to buy pre-made supplies for long-term survival is at a discount grocery store. Buy mislabeled, off-brand or discontinued tomato sauce, canned soup and canned vegetables.