Add these factors to the recent sale of a whole lot of new firearms, including those chambered for .22 rimfire cartridges, and the general public's continued hoarding of what .22 rimfire ammo does make it to the shelves, and you should have a fair idea of what's going on.
Eventually, I suppose, people will get tired of tripping over bricks of .22 rimfire cartridges they've bought up whenever they saw it on the shelves and the market will settle down a bit. But until then, I guess you're either stuck with trying to compete with the hoarders for narrow windows of purchasing opportunities, or paying a ridiculous premium for ammo that is selling at scalper's rates on the resale market.
Or, heck, go out and find those opportunities to buy and scalp those rounds yourself. That's capitalism. And for the moment, the average US citizen still has the legal lattitude to make that buck.