Food choices are simply a matter of growing and expanding your tastes in food and beans and legumes are an excellent source of many nutrients and store well for extended periods of time.

Oats and other grains make for a nutritious breakfast along with powdered milk and snacks of popcorn add variety to your diet.

Seriously do you believe an inexpensive source of food that you enjoy can be easily found consider this will you be that fussy if conditions precluded obtaining foods that you prefer.

As a child I was not allowed to be picky and spoiled as my parents monetary resources were limited thus if I turned my nose up to something nothing else was offered it was that simple.

If you are on a budget and looking for nutritious meals then some sacrifices will be encountered.

Here is a start for you:

Small Red (Chili) Beans - 40 lbs - $72.95
Pinto Beans - 41 lbs - $65.95
White Rice - 44 lbs - $57.95

Breakfast
Quick Rolled Oats - 19 lbs - $31.95
Oat Groats - 42 lbs - $57.50

As a start for a soup stock for lunch
Pearled Barley - 44 lbs - $49.95

Instant Nonfat Dry Milk - 56 oz - $17.95 $
Instant Fortified Milk - 21 lbs - $94.95

Desert
Yellow Popcorn - 45 lbs - $59.95

Emergency Essentials - Be Prepared Emergency Preparedness Food Storage
[link to beprepared.com]

Update:

Peanut Butter Powder - 44 oz - $16.75