I'm in Ireland, I'd say a good third of printed on labels are not even in the right currency, as companies have a single UK and Ireland SKU. It's also understood that generally it's the retailer that sets pricing, not the manfucturer, so when a book has $9.99/£8.99 printed on it and a store sticker with €12.99, nobody is confused that that's not the exchange rates, or about which price they'll pay.
I'm also in CA and lived on Arizona for most of my teens and early 20s. Never saw this pricing. I would have remembered it, especially during the skint college years. It's always been a dollar. At best you'd see 2 for 1 deals.
It sounds like you live in a heavily subsidized market - probably best not to try to draw generalizations about inflation from your specific circumstances, they are atypical.
I'm in Ireland, I'd say a good third of printed on labels are not even in the right currency, as companies have a single UK and Ireland SKU. It's also understood that generally it's the retailer that sets pricing, not the manfucturer, so when a book has $9.99/£8.99 printed on it and a store sticker with €12.99, nobody is confused that that's not the exchange rates, or about which price they'll pay.