FWIW, raw large flakes oats make a delicious alternative to regular breakfast cereal, you don't need to cook them and they're still edible if you only have water, but milk is nicer. Juice works too. The original museli... add whatever other seeds and fruits you can scrounge up.
Throw some peanut butter in your morning porridge and you'll be full for hours. I eat a lot of oats and they're one of the best foods going if you ask me.
Couscous could be soaked instead of cooked but you'd likely need to soak it all day. If you're really serious about not cooking, learn to eat the "raw diet" that is faddish these days; meaning it'd likely be more than 15$ a day unless you eat oatmeal and tinned veggies ever day.
Lentils are an easy, cheap and nutritious meal. Onions are cheap and tasty, the dehydrated ones are cheap enough if you want to save some weight/space. Textured vegetable protein is another cheap staple that is versatile. Wikipedia says not to eat lentils raw though, but you can make a small pop-can stove pretty cheap so I think I'll pile-on with the 'you should cook' suggestion too
