Quoted:
Good advice. Always store what you eat and eat what you store.
I like bread made made from fresh ground hard white wheat and corn bread made with fresh ground corn. Popcorn is always good. I like dried apples, rasins, and other fruits.

I have a few case of military freeze dried pork chops, that I bought a few years ago. I have eat some that where 20 years old.

I've eat 20 year old MRE's also.

Quoted:
MRE expiration is not so simple as a date on a box.   People throw away a lot of perfectly good MRE's.

Some of the older dark brown bag MRE's were, depending on your tastes, awful.  Mostly it would be a single item that sucked.   The rest - the crackers, the JB weld peanut butter, etc, were perfectly fine if you had sufficient water to digest them, and would really hit the spot after a hard day of working your ass off.   Saying that one would rather not eat them, assuming they meant not eating any of the MRE, shows a fundamental lack of understanding of just how truly awful food can be or how hungry people can get.

I ate my last old school brown MRE components a few years ago; I had them for almost 20 years.

The newer tan bag MRE's are mostly awesome.  There will always be one or two entrees in a case that you don't like, but for a group of people those dislikes usually don't overlap, allowing everyone to eat something they're OK with.

Does this mean people should buy a mountain of MRE's?   No, not at all.   I don't own any and don't plan to; the ones I had before were free.   But you will not find a better meal for use in a pinch that requires absolutely nothing to prepare but enough water to drink with it and to use the heater.  People should appreciate them for what they are.

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Regarding cheap food; I think it's important to separate that the OP has learned a lot of lessons and has their food situation in hand to their satisfaction, and the comments about longer term prepping not having value.

The normal human condition is that you are lucky if you're able to sock away enough boring food with a long shelf life and some suitable extras (spices, preserves, etc) to weather ups and downs.  Some people are going to go heavy on rice and beans due to simple personal economic reality, and even that is an improvement over what most people in the world can manage.   It's common in many other parts of the world - and was much more common in the US in living memory - to have a much larger supply of preserved and storable food on hand.   I had relatives that grew up in boxcars, and they had lessons to teach.

The idea that being in North America in the 21st century is some magical talisman is what is irrational.  The problem of having food while your neighbors have none is not new; there are no surprises there for anyone not living with rose colored glasses.    You either have enough allies to keep what you have against those who would take it, or you don't.   Not living on a mountaintop doesn't change that - it simply changes what you may need to do to and your odds of success.

Stating that people will take your food doesn't really mean anything; if they're willing and able to resort to violence to take it, then you can violence them right back, and you should be in a better position to do so if you've been eating better. It's not practical for any length of time for 2 people, but 1-2 dozen is an entirely different story.  Being ready for that is part of the equation.

I have been through the personal problem of what to store and how much, what gets used, what gets wasted.   It's not all that difficult with the barest minimum of cooking skills and sufficient medical training - the biggest pitfall, as OP points out, is sinking a ton of money into expensive food of dubious edibility.   Even if you don't intend to rotate something regularly by eating it, you need to try it first.

I think camping and especially backpacking - as increasingly few families actually do anymore - is enormously valuable for teaching lessons about cooking, how far certain amounts of food and water will go, and the value of different foods in different situations.   Adversity changes your perspective.