The prepackage freeze dried kits are expensive. To save a lot of food cheaply, I chose to fill 5 gallon buckets, with mylar bags and oxygen absorbers. I have twenty buckets: flour, rice, dry whole milk, beans, peas, eggs and other stuff. (now I’m going to have to do an inventory). In this configuration the food will store for 20 years. Downside is the buckets take up a lot of room. I bought most of my stuff at Walmart. There are many sites to buy bulk online. Amazon being one.
Note: Bread flour is different than all purpose flour. I made a mistake on this one. I also got a cheap Amazon bread maker. Works pretty good.
I have can goods but the shelf life is two years and the stock has to be rotated. Key items are oils, sauces and spices to add taste. A diet of rice and beans can get boring fast. Don’t forget booze if you are so inclined.
I have a freezer full of cheap meat: hamburger, bacon, chicken and fish. When that runs out, I plan to restock it with hunting and fishing.
Since water is essential, lucky for us we back up to a catch basin. We (neighbor and I) bought a fairly expensive ($600) water filtering system. I had the filtered water tested and it came back pure. Just today we talked about getting a water pump.
My neighbor and I went half on a substantial generator and had it converted to run on propane. This solves the fuel storage problem.
My neighbor and I have substantial inventories rifles, shotguns and pistols. We have about 50k rounds.
I have a big first aid kit and save medications in a metal ammo can with silicone thingies.
If you are starting from scratch, it could seem like a daunting project. But if you treat it as a hobby, you can quickly build a substantial inventory in a year.