Hoarding food is buying a lot of food and then not using it, throwing it away when it is past the use date. Buffering is buying things that one would otherwise buy later anyway, but buying them sooner so that one creates a buffer of food/water. Buffering is in principle zero cost, and if one gets sick one doesn't have a food buying problem either. A potential danger is that one could get sick if the buffered food gets eaten past the date it gets spoiled. Buffered food can save effort when one does not want or is unable to go out to buy food for some reason.
If "the masses" have a lot of food between them, even if criminals have food available, then the total chaos in society during a big problem will be reduced immediately. Criminals will also calculate their own self interest: if they have no food they will take more risks by obtaining it through violence. Buffering works for a lot of disasters, from war to revolution, and natural disasters from flooding to earthquakes and even a global crop failure (if the food lasts until the next crop season).
Compared to food/water, all the rest is luxury (except for shelter in difficult climates, but shelter is probably already standing and if not could be build if one does not have to go out to find food). Money would likely be without value in most catastrophic situations. Its value can easily be manipulated by the Government, which means it offers no protection for the People if the Government attempts a People hostile tyrannical coup. The Government would simply destroy the currency and the people doing it get rich. Valuables will still need to be converted into food/water. Few people are interested in useless gold trinkets when one would be dead in 4 weeks without food. The blade of food buffering cuts on both sides because with the food available the hands of the productive and lawful people are free to do things. The things they can do they can decide for themselves at least for as long as the food lasts, individually or in groups. Hopefully that will be long enough to solve the problem, and bring society and the economy (especially farming and food distribution which is obviously fundamental) back.
Before these things are possible during a disaster the food will have to be buffered by a significant percentage of the People. If not the parts that are without food will be occupied with finding food or they will eat together through the available food so quickly that the problem can not be solved in that little time. If 10% buffers food for 6 months that would feed 100% of the People for 2 and a half weeks. With a plan to solve a problem, a lot can be done in 2 weeks. Without a plan little may get done in 2 weeks. The food/water would therefore only be enabling whatever plans are there, whatever the People actually get done during the time they have food/water. The food and water alone is not enough. Different disasters require different solutions. For how to handle a revolutionary or injustice problem, see socialism.nl.
One of the problems of food buffering is that some diets do not allow for significant buffering. This could be solved by changing the diet, or by changing into hoarding of very long lasting foods. Those foods could later be donated to some good cause.
Buffered canned food that expires in 1 year, divided into 12 steps for each month.
Buffered drinking water.
Some food in bulk.
Total costs so far: 0,-
A way to buffer much more water then is practical using bottles, is (for instance) a water butt with drinking water. Obviously the water would need to be actively used, quick enough so that it does not stand still. To keep it good presumably the water needs to be replaced all at once every so many days (or months), especially when replacement rate is slow. The bottle method is obviously cleaner because it gets refreshed in whole per bottle, so that is better to be used for direct drinking normally, while the water in a water-butt could still be normally used for washing only. If kept clean enough in an emergency situation having about 160 liters of probably good water is potentially better then nothing at all (depending on the type of problem obviously.) (A water-butt costs some money of course, but not a lot (here.))
Note that food/water-buffering is good for everyone (if done without health risk), because it diminishes directly the pressure on emergency services. Then there may be people who think "someone else will take care of me, even for no reason." That may be true, but such thinking puts more pressure on people who do go to the trouble to create some safety buffers, then they have to buffer even more for the people who build in no safety margins at all.
To bake/grill/cook/boil food/water, one would obviously need something that can burn, be that furniture, clothing, or whatever, such as fuel for a fuel burner. Food/water reserves matching supply of fuel might come in handy, so food it doesn't have to be eaten raw, which is less save too.
I suppose for really long term survival planning it may be a good idea to have seeds that will grow easily in the local climate. Some seeds last a long time, many years. They are also very cheap (in Holland.)
In a hypothetical situation, where everyone does all the above, then even after total catastrophe (of some kinds) many people could stay alive until the next crop season starts, and in theory then grow crops either professionally and/or amateurish. Having a lot of distributed resources means far less fighting over remaining resources, and much more willingness to share them (because there is enough.) Survival (so they say on TV) is "very much about the will to survive." When there is water & food, and a realistic possibility to make it short or even long term, that will definitely be good for the will to survive. If there is a realistic possibility to survive, that means hope, which can translate into a stronger will to try to survive. It may end up being the will to survive that causes survival, rather then whatever supplies. A good start is half the work ? In the short term having some buffers will make the psychological shock of a disaster less, which can eventually make a difference.
(Capitalist societies are expected to turn into the chaos of war and tyranny because they bring evil people to power that exist, who will be causing such things to happen. The worst and most competent people will get power. That is more or less the top of organized crime and the worst of the worst of business leaders, and this group degenerates over time toward more abuses and more competence because that is what makes them more fit for survival in their biological niche within human society. It is both something that can be predicted by theory, and proven to happen by history. It should be survived and resisted, which will be hard without food/water. The best chance to resist these things is in the beginning when the evil ones attempt to take more political power and eventually start wars. It is a strategy in some/the elite circles (though this may just be a rumor), who have time all day long to scheme about how to establish and consolidate their stranglehold over the planet, that you can control a population and force them into submission by controlling food/water, which is of course correct (and hence the rumor is more likely to be true). This control will be easier when the public has no clue about what is really going on, which is usually the case. Hence not only is the potential lack of food/water an objective problem, certain people are actively looking into this lack of defense by the public and are theorizing on how they can exploit it for their goals. Tyranny is the goal, as usual, throwbacks to the days of the naked apes. Power and survival is what they want. How do these people get power ? You put them into power with your laws that allow for profit finance. But they are not on top of the planet because they are incompetent idiots. They are both bad and smart. Why do you think bad things happen in the world ? You put them in power because you thought beer was more interesting than economics and the size of your car more interesting then history (those who resist the tyranny of capital know who they are). Didn't know ? Did you try to find the truth ? It is not really hard once you know how it works. But even if it is a difficult problem, an accidental gap or a gap on purpose in a boat: the boat will sink either way. It is same for economics and finance law as it is with a boat. Because of these problems it is useful to have food/water for some time, to boot up a plan that will work and solve these problems (once and for all time, since it is now proven what the problem is, and the problem is solved, there is no reason to make these mistakes again.)
A model for the things that might be needed could be the great depression from 1929, which eventually degenerated into the second world war.)