When was that?
.22 ammo prices were at about 2 cents a round for a long time. (mid 60’s to the 1990’s).
I was too young to be buying .22 ammo in the 50’s. Inflation shot up post WWII and continued right on through the Carter era. Then the inflation slowed for a while.
I can recall buying bulk packs at a little less than 2 cents a round well into the 1990’s, on sale.
Friday was payday, and I'd stop at Woolco and get a brick of 22 LR for $4.95 (don't remember the brand but could have been Remington or maybe a generic).
Gas was 30 cents per gallon, and beer was around a dollar a six pack. Non-premium beer was 99 cents per six pack and your "premium" brands (Bud or Schlitz) were something like $1.15 to $1.25 per six pack.
Add it up: $4.95 + $(4 * 0.99) + $(3 * 0.30) = $9.81