Start with things that benefit you now and add others as you can afford them.
First thing is to start an aquaponics garden. This can be large or small, indoors or out. Use (and stockpile) only heirloom organic seeds. This will give you more vitamins than any store bought produce because nutrients are created in the veggie during the process of ripening ON THE VINE. Produce that's picked green to ripen later have roughly 5% of the vitamins and nutrients of home grown. Also, in an aquaponics system, you don't need high dollar chemicals because the fish provide those. You can also size the system to yield 4-6 lbs of fish per week after it's been running for 6 months or so.
Then, power the system and eventually your home needs with solar PV as you can afford them. You don't have to buy the system all at once unless you want a full grid tied one, which is not worth much in revenue, or even a full retail. There are many deals that can be found for less than $1 per watt. Spend/save more of the money on battery backup but don't purchase all the batteries too early. Stagger them. They only last so long.
In conjunction with the PV, you can build a number of different projects to heat water or air from the sun. Many of these integrate with hydronic heating systems, have A-coils for your furnace, radiant floor or overhead radiant.
Then, when you can afford the energy, get an atmospheric water generator. This is basically a dehumidifier (goes well with the aquaponic system) that makes up to 5 gallons of purified water per day. Many offer low maintenance filters and hot water taps. Some even can be tied into your kitchen plumbing.
Buy a freezer and have a pasture raised, grass fed cow butchered for meat. Same for pork and you can even do this with chickens (with you doing any combination of the work). Don't forget that if you have the land, that chickens lay an egg per day so if you're desperate for protein, you can always count on an egg count close to the number of chickens you can keep.
You can use excess in any of these areas to barter for milk or dairy, unless you want to also keep some goats. You should also take a week and ask yourself "if you could live without this" regarding everything you use. Things like toothpaste, soap, olive oil all have substitutes and you can make many of them at home, but you will probably just want to stock up on much of that stuff.
Doing things like this will both cut costs before a crisis hits and will sustain life and finances afterwards. I'll leave the rest of the suggestions to others here since I'm not so educated on armament (I prefer bow hunting) or current metals deals.
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