Canned chicken in bulk packs (2 packs or even six packs) is the lowest priced source of shelf stable meat. Meat can be preserved by freezing, drying, or canning. Obviously freezing exposes you to the risk of losing power. Dried meat is expensive, and while I like beef jerky now and then, I wouldn't prefer it as a staple. That leaves canned meat as the best option.
If you look at the price per pound, canned chicken comes out the best. Canned chicken is very good with rice and other casserole type dishes. Canned beef is surprisingly good with rice as well, and canned hams would be good with beans or split peas. However, these cost more per pound. Finally, there's Spam, which I personally like. However, again, this is more expensive than the chicken. All of these should be good on the shelf for 3-5 years.