Companies selling “prepper packages” are 90% ripoff. Quality tends to be poor. Most people say Mountain House has far too much salt. MREs are only for taking food with you on the road. Otherwise much too expensive.
I eat what I store, and store what I eat.
Large quantities of dried beans and rice will keep for ages and provide a basis for all kinds of dishes. Pearl barley ia also very good for giving soups some body. I like to keep a lot of canned corned beef hash, because it can be eaten cold if you have to. Smuckers real peanut butter stores well, I buy more when the supply gets below a dozen jars. (BTW the empty jars seal extremely well, don’t throw them away.) Pacific Foods sells good quality boxed soups that store well. Honey never spoils. Tomato anything in JARS, not cans. Canned sauerkraut - high in Vitamin C. Just some ideas I have followed for two decades.
Having a pressure cooker is a must. My big electric CrockPot rarely stays cool for more than a couple of days. It is NOT, however a canning cooker. In case I’m forced to go without electricity for an extended period, I still have my old stainless steel Presto.
Corned beef hash is great lots of calories and fat
I also keep canned ground beef and lots of canned salmon (canned salmon is ectremly calorie/nutrient dense)
Beans, rice, cornmeal, canned stuff that requires no water.