Agreed, nuts are extremely healthy and delicious. However, they tend to be on the pricey side of things. When absolutely scrapped for cash, a cheap diet for me would mostly be beans, grains, and lots of veggies. For $10 you could probably prepare an amazing bean soup that's enough for 20+ servings. If you buy nuts, $10 would barely be enough for a couple of jars worth.
I would like to eat healthy food but I am low in budget. One of my friends suggests me the following food. Broccoli Onions Sweet Potatoes Carrots