We have an Amish community near here with a a great store selling bulk foods and such, they have 25lb and bigger bags of dry beans , rice, etc.
I am tempted by the bag of Garbanzo's, I heard a couple ladies speaking of combinations of grains and/or beans that can provide complete proteins, but don't recall right now, a good subject to research.
It seems dried egg powder would be a good source and very reasonable.