On ammo that is. Basically, how much x39 for three  arms in this caliber?

This depends on how much you're willing to spend and how much room you have to store it all.
Many members on here buy a crate/1000rds or more when deals come up, same with magazines, which you should be filling with that ammo you're buying.
Personally, I'd want a baseline of 1K rounds per gun, minimum.

The saying here goes "Buy it cheap, stack it deep".

30k across all calibers

For the most part I wouldn't say youd ever lose money on it.  as long as you keep it free of rust I consider it an investment if you don't use it.

as much as you can afford unless your guns sit for years

Depends on how much you shoot

I like to have 20k+ combined

When you run out places to put it.


Who knows what the future of imported ammo has for us.Buy when its cheap or cry later

I try to buy a case when it goes on sale and I currently have 4500 rounds for 2 ak rifles. This is plenty for me since I mainly shoot AR's. My aks go to the range about once a month and get a mag or two fired through them.

I like to have a minimum of 1000 rounds of quality FMJ stashed that I do not touch for each gun that I shoot in addition to the rounds that I plan to shoot. (I shoot all of them, but some very rarely)

If I have several then the number may drop a little, maybe 500 each for each rifle above the fifth one.

I also like to keep about 200 rounds of quality SD ammo per gun.

2000 to 5000 per caliber.  More is better.

Never enough.

Yeah, but when are you adding more 5.45 GT to that stash of yours?

We used to say, and I still do from time to time, "how much can you carry on you".  If and when the SHTF happens, that might be all the chance you get to carry what you can.

This. I don't stock up in fear of zombies or blue-helmets. For me it's primarily about economy. My sons & I just a year or two ago shot up the last of a batch of 9mm fmj bought at Academy during a sale. Fifty-round boxes still had the $3.99 stickers on them, which made it a lot less painful to blast away recreationally. Similarly we still have some x39 bought at (iirc) $84 per 1200. I do reload most of my calibers, but it's still a good feeling to have a bunch of cheaply-bought factory stuff on hand. For my use, my now-grown sons' use, or their kids' use, whatever; much like having deep stocks of any consumable whether motor oil, fuel, or whatever.

I buy as much as I can afford as much as possible. Usually around 3k-5k of various caliber a per year.

I like to have a min of 4,000 per caliber and much higher for 22LR.

I like to have all of my 30+ magazines loaded, a 30 Cal ammo can full, a 50 Cal Ammo Can full and a Spam Can.

Right now I have the 30+ mags full, the 50 Cal Ammo can full and the Spam Can.  I'm almost there.

As much as you can afford!

 

at least engough to get through any price spikes and keep shooting . Look at 22 ammo as an example .

I like to keep 1000 in reserve for every firearm, after that as much as I can afford. Though I will say I do take into account what I'll realistically fire in a year, and go off of that. To me there's no point in having enough ammo for 50 years' worth, as I can be spending that money on something else.

For each caliber, have:
What you shoot in a year's worth + 1000 (500 if fullsize rifle round, 5000 if 22lr)

My rule of thumb is at least a year's worth of ammo for every firearm you own, ammo prices bounce around worse than gas prices so being able to dip into your reserves when the prices shoot up is just smart. I stock WAY more than that though, a lot of it is surplus ammo like Yugo M67 and 7N6, surplus ammo never stays cheap forever. But when it is cheap, I buy it.

Lately I have been buying a case of 1000, shooting 500 rounrounds, buy another 1000, repeat.

 

You can never have too much

I always keep a minimum of 1,500 rounds per gun long-term, and then try to keep at least 500 as leeway for practice/plinking in between times I can't get ammo.  Then whatever on-top of that I can afford to stash.

Honestly, my absolute MINIMUM is 1K for each gun I own. That would be maybe a 80/20 mix of range fodder and defense loads.

That being said, look for deals. They pop-up from time to time and be ready to pounce.

Whatever amount you can comfortably afford to buy without going into the poor house, the last thing you want to do is buy ammo (or anything else) if its going to affect you or your family's ability to pay bills, or affect you or your family financially in a negative manner, no one is going to have the same "comfort" level. Myself personally, I don't buy during a panic, I buy when its either on sale or a reasonable price, same with magazines. I buy for economic reasons, ie price increases due to import bans or panic buying, this way I don't have to worry about paying astronomical prices or none being available for an extended period of time.

There are a several ways that can help mitigate the cost of ammo and magazines.

1) If you have friends who consume the same caliber who are local that you shoot with, you can split the cost then divvy up the ammo accordingly.
2) Have a friend(s) buy it when its on sale if you cannot afford to buy it at the time and then repay them when you get the money, I would suggest only do this if you can afford to pay them back in a reasonable amount of time.
3) Set change aside at the end of each day, you'd be surprised how quickly it adds up, then buy ammo when you have enough to buy it.
4) Set $10 a week aside, in a years time you'd have $520 or in six months you have $260, or whatever amount of money you can set aside along with the change, you could buy a sizable amount of ammo over 12 months time.

What's considered a good price right now? I see 700 rnd spam cans for $170

Actually this helps ammo prices return to normal faster as the ammo from your stash helps make up for the increased demand.

Supply and Demand how does it work?