You look at the price of a combo meal at any fast food joint vs the calorie content, taste and menu options on the MRE, the costs are pretty comparable if you shop around.
Shopping around, you can do MREs in the $60 per case range, gambling a bit on age, but $80-$90 is retailish. Over $100 and someone is price gouging or taking advantage of local market conditions. I would be charging $100 per case maybe for brand new stuff I already hauled out to the middle of nowhere.
You look at most of your fast food joint value meals these days, they kill most of a $10 bill. Sure you will have a one and some change left over, maybe a couple ones and some change, but that's getting it without any dessert. You start looking your average Denny's meal, its right in there (except Denny's starts looking pretty good compared to an MRE). Your basic military chow hall food is supposed to be using Denny's as one of the benchmarks, as is your basic government service contract per diem pay (based on a cheap motel plus three sit down meals a day at Denny's).
Mountain house is NOT a "complete meal" it is one good sized entree. Now what you could do is set up a daily ration pack with one MRE, one Mountain house "meal" entree, and then a couple of protein bars and energy shot drinks.
Water, you have some in the pack, some in the vehicle, and refil the containers along the way. Your actual canteens it is best to store empty. If you think it is smart to store canteens "loaded", realize they are opague, and you don't know what funkiness is in there. If you want to find out, fill a few canteens and at the same time fill some clear plastic bottles that you rinse out. Come back and look at the clear ones after a month, and all that shit you see floating around in there is also floating around in your canteens, you just never saw it.
For that reason, I suggest storing commercially bottled water. A bunch of companies now make canteen pouches for commercial bottled water, and it is not hard to improvise some ammo pouches for that too. That means you have on your gear just ONE GI canteen kit with the cup and stove stuff, then maybe a hydration pack. The rest is about commercially bottled water stuffed all over spare nooks and crannies in vehicles and cache spots.
I will drink from a canteen only if I am desperate and ran out of bottled water. What I use the canteen for is wetting the do-rag and or face towel. Fuck that face paint bullshit. Constant cleaning and wiping around the face and neck, not getting that salt buildup on my face which in turn stings and blinds me. That's what the canteen is good for.
You make a cache spot for something, you bulk that out with commercially bottled water, most likely obtained locally. Long term, sure ammo and mags are worth more, but short term, operationally, that water is valuable and important, you don't risk everything going to shit with funky water stored long term in short term containers.
Another factor on bulk food stuff like rice and salt. You don't haul that around. I see guys doing rice in bugout bags, and I am thinking WTF? I have rice at home, rice where I am going, I am not carrying or boiling that stuff in route. I am not even really all that big on the mountain house, since that means I have to either boil water or find hot water somewhere.
Someone suggested once using the hot water dispensers in convenience stores, truck stops or fast food joints to reconstitute the Mountain House food. Heck, if I am going to an intact convenience store, fast food joint or truck stop, then that $5 gets me fed something too...I'll do a couple of 7-Eleven hot dogs smothered with cheese and chili with an icey long before some mountain house. I mean really, anything freeze dried is not that good compared to the junkiest junk food. Then differences in prep time. Stopping to cook and prepare food gives too much opportunity to hostile parties unless you are running a convoy op where you want to stop and set up chow hall at a rest stop, then you are not talking bugout bag food any more either.
Bugging out means bugging out, not recreational backpacker stopping to do culinary arts picnic while snapping pictures for an adventure tourism article in some website or magazine.
Wad of small bills is a survival item too. $100 in $1s $5s and $10s will get you fed on most road trips and walkabouts where there is any infrastructure intact.