What kind of diet? Low carb, low fat, gluten-free, vegan/plant-based, vegetarian? I'm a proud orthorexic plant-based person so some of this may not work for you but I am a firm believer in fiber in the morning. Bowl of raisin bran + almond milk + ground flax seed = $0.60 breakfast A cup of old-fashioned oats + ground flax seed + 2 cups of water + 15 minutes boil = $0.25 breakfast (don't use quick or instant oatmeal...it is too processed and jacks up your blood sugar and you'll be starving an hour later) 4 or 5 spotty yellow bananas = ~$1.00 breakfast Tomato/breakfast beans on toast with little bit of margarine and seasoning salt (Van Camps pork n beans or Van camps vegetarian beans in the US or Heinz beans in other English-speaking countries) = $1.20 breakfast Toasted wheat bagel with cream cheese (or tofu cheese) = $0.80 breakfast Avocado slices & tomato slice on toasted wheat topped with ground flax seed ~ $1.00 breakfast Other ideas: If bananas are about to turn, peel and freeze and make smoothies with them later Buckwheat + flaxseed pancakes Tapioca pudding Pea protein powder + fruit smoothie Steak & Egg McBeetus with extra cheese, salt, and margarine Chilled tears of children and the elderly Boiled beets + salt & pepper Etc...