Man, those bring back memories...
I'm an old guy (at least older than a lot of you) I remember buying those at 25 cents a box for a LONG time, then they went up to 45 cents and I thought the world was ending.
I hunted all over for them at the old price, bought any I could find. I think I wound up with about 1500 rounds. I went through those and many more that summer, and 45 cents didn't seem like that big a deal by the end of summer.
I'm sure I went through 10-15,000 of those in my old Cooey single shot. That old gun was so shot out you could close the bolt by dropping the muzzle quickly; the bolt would wobble forward and drop home on it's own. I kept shooting it like that for quite a while (didn't know better). It's now LONG retired, but I still have it.