It is not just little shops that have been doing it, but individuals as well. I have heard of it from multiple locations.
The market was short circuited by the manufacturers refusing to raise the prices to wholesalers to any appreciable level.
In a free market, manufactures charge what the market will bear, until supply and demand curves cross. If they are making lots of profit, manufactures increase production, and prices drop.
But with .22 ammunition, the manufacturers did not raise prices to reduce demand to producition levels, and neither did Walmart, creating the situation we have seen.
I picked up a bunch of .22 in Florida when visiting family. Cabellas had plenty.