Sitting on about 15 varieties, really only make heavy use out of about 6-7 of them.
I learned in the famine 4 years ago to branch out and try some different powders besides sticking to just my favorite ones. So I can use the other powders because I developed data on them already. But the powders I use most I've tried to get at least one 8 lb jug of if they had it, or five 1 lb cans.
I also learned to buy when I saw something I used whether or not I needed it three months, or even a year from now. I made a trip to the local shop maybe once every six to eight weeks and bought little bits here and there. Spent nothing more than a couple hundred a trip, maybe less than a hundred others.
Fortunately going into this I'm sitting on about 20k in primers, 12-13k in bullets, and 45-50 lbs of powder.
Of course, it's all spread out across maybe 8 different handgun and 8 different rifle cartridges.
For example, I shoot High Power service rifle matches. I've only got about 4,000 small rifle primers. That's pretty much one year's worth of matches, plus some practice in between. Then I'm out.
So fella's, when things get back to normal, do yourselves a favor and buy a little bit each month or two. For some folks a little bit is 2 lbs of powder each trip and 1k in primers every other. For me it was 1 or 2k in primers, 4-8 lbs of powder each trip.
Some guys will do the big bulk order thing from Powder Valley or Graf's, and I've both organized and participated in those with guys at my club before. The challenge is saving up the money, and placing the order when all the different stuff you want is actually in stock.