I like to shop at Sam's Wholesale Club for canned meats -- they have the best prices, but you have to be willing to store some, because you have to buy a year's supply sometimes! I get my dry cell batteries there too. I also shop at Wal-Mart for a lot of my supplies -- they have great deals, and if you plan it right and catch them switching out inventory as the seasons change you can get some great deals on clearance racks. I buy a lot of gun cleaning supplies there, gas cans, large (six gallon) water containers, propane, medical supplies, fishing tackle, camo clothing, etc. I like Tractor Supply for boots, gloves, and farm supplies. I shop Lowe's and Home Depot for building supplies and tools, and I use Dollar Stores as well, although I think Wal-Mart has better selection and prices. We also have major sporting goods retailers, and I shop them but only when they have sales (I browse online first) because their markup is way too high.
I checked out the Wise and Mountain House emergency food supplies. I decided I could easily beat their prices buying from Wally World and making my own emergency food supplies out of food I know we like to eat, and save money. A bucket of Wise food cost ~$109 on sale, and for that kind of money, I can fill up a whole pantry with foods we like in cans and packages.