I've been a bad boy and kind of lazy (kind of?) During the economic problems of the early 1980s I bought primers. They weren't high and they were available. More so than the money to buy them. It kind of over did it back then and I've got a mix of brands (all American). Because of my primary usage of SPP and some LPP, I just figured I had plenty for the rest of my life. Who knew I'd get this old and nasty. Anyway when 1994 and the Klinton gun banners were going full steam, I decided I should just stuff primers in all the empty shells I had.
Then for whatever reason I began shooting 9mm and realized I was sorely short. My oldest and I both bought Berettas and I figured I needed an ammo splurge. I'd already loaded all the 9mm brass I had, so we went to a gun show up north. It was Dayton and one seller made me a deal (have I got a deal for you kind of thing.) He sold me 4,000 once fired for about $100 total. Did I mention I had a single stage press? So I fabricated a press mount out of an old chair. After that broke I mounted the press on a board and then the board to one of Momma's good stout dining room chairs. C clamps were the deal that saved my life. Anyway, sons were living at home during that period and we spent many nights pulling the handle. One step at a time! Ammo cans filled to the point they hurt to pick up. I have no idea how many fit in a .50 cal can. They worked real well in a succession of guns. First the Beretta, then the S&W M39s. Still fire just fine in my P210s.
Somewhere along the way I've bought a few thousand more primers. Not necessary because I still must have enough. And now I've got a minor shortage of LRP.
And I just looked at some notes that related to the cost of ammo/reloading. All of them use the $8 a thousand price for primers. Powder was cheaper then, too. I've never cast very much, but had the molds and handles. I gave away my Lee casting furnace. Son now mad because he's into casting. Even my wife loved casting but we didn't do much of it. At the big Louisville show I sprung $100 to buy my oldest a luber sizer (RCBS) and a Lyman 4 gang semi wadcutter mold with handles. I thought that was a bargain.
I guess the point to my rambling is being prepared isn't something you can do all at once. It takes years and years. Then we get creaky and die I guess.