Isn't bulk just abbout almost always the way to go, if you have room to store? For a couple, six months of food is going to weigh probably at least 500 lbs. and take up maybe 11 cubic feet of space. If you never eat the stored food, much of it will go to waste, as sooner or later it should need to be replaced. Buy in bulk, rotate stuff out of it. Just brought home 50 lbs of rice from Costco.

Sunchokes are one of my new favorites. Grow almost anywhere, look attractive (tall sunflowers) and most people would not know they have an edible tuber. My friend from the Ukraine refers to them as a "ground potato" fit for feeding to cattle. Wholefoods charges a couple bucks a pound.