What would be a good "all in" , buy/sell price on private stash of #10 cans and various 3 day buckets (freeze dry pouches)

Est 150-160 #10 cans, various makers, etc

What are they and how old are they?

MountainHouse, LDS, Augusta Farms, Essentials. Age various from 15 years to current.

Not really enough info here for good answers.

What types of food are in the cans?? Big difference between all of those cans having meats in them and having mostly carbs.

Couple of years ago I answered an ad for a lot of dried food cases ( #10 cans boxed)  I showed up to find 210 cases of misc. I paid 100 and loaded my truck. Sifted through them and took 10 cases to a local auction selling them for 200.
  The stuff is older but edible.  If I were really hungry I would use it.  Those deals are becoming less frequent, although I still search.
Once bought around 250 superpails of mostly Hard red/White wheat , beans, pastas, banana chips and oats, honey and molasses for 600.  it is getting past date though. I am sure it is still good ( i hope)
  I always do local search for this stuff. Got a little more educated on searching for date codes :)

Not hung up on price these days as much as the feeling of having security.

Who on earth is selling this stuff now? The widow of recently deceased prepper who doesn't think she should keep it and wants a fast cashout?

Those knowledgeable are certainly not doing so given the global and national circumstances, and those who aren't are not exactly likely to be able to give you good answers regarding calorie content, storage conditions, etc.  That would certainly play into a lowball offer from me, where I in your shoes.

I bought about 200 #10 cans from A LDS family leaving the country for a mission trip for $275.

Are you tryin to make a buck to get new food?

Why not just start eating it, and you will save money as opposed to buying more food?

Or did you realize we have been prepping for 20 f'ing years and still nothing..... Even though it looks like crap every 5 years or so... I think we have all been taken for fool.... Keep em spending, and keep changing crap so they cant figure it out... Dunno, I'm drinking too.

If 15 years in climate controlled storage, there is no way I would sell any.

As for buying, can you trust the conditions stated over the last 15 years?

This might not be all bad an idea. Rather than spending a whole bunch of money buying a year's worth of food at once, why not buy, say, a month or two's worth at a time. Then, once you've got however big a stockpile as you think prudent, just start eating it and replacing what you eat with new stock. That way, you always have a stockpile but some of it is new, some of it older but nothing older than maybe 10 years. Granted, you may be paying more to replace what you have than when you bought it but that's what inflation does over time. There's a tradeoff between having newer stock and paying more for that newer stock.

Huh, no super deals but some decent stuff on my locals craigslist
$3/bag HDR meals, delivered, if you buy a pallet (48 cases = 480 days/bags)
https://dallas.craigslist.org/dal/spo/d/arlington-hdr-mre-pallets/7470564349.html

yes! this exactly. While all of my finds have come from private party I do search quite often.  Sometimes there is a great score.  Estate liquidations and moving are typical reasons. One guy sold me 3 cases of MH chili mac for 30 dollars...looked brand new, said his girlfriend bought it and she left it when they split up.  Sorry for your loss bro,....but Thanks!!!

But regarding op, If you can afford the price and it's good to go.  Go for it!   Rather have and not need than need and not eat.  I got on this kick after Rodney King riots in LA.  We had maybe 3-4 days of food in the house and going to the grocer was sorta sketchy at best.  

I bought a freeze drier a few years back but we don't run it like we should :(  
We have a metric ton of egg bagged up though,  I am currently building a new chicken fortress to replace the dilapidated shed that was available for the last few years. we lost many chickens to predators over the years. the last straw was last fall when a dog got in and killed all ten.

   This one is gonna be bomb proof, gotta take care of the little layers currently brooding.

The humrats are vegetarian and from what I sampled we're actually pretty tasty.  These were mfr 2019 and reinspected 2022. Ymmv