I play what I call the Wal Mart Ammo Lotto - you just have to be there at the right time. They have a 3 box limit, so one person doesn't buy them all. They do get them, usually 12-15 boxes at a time. Same with 9mm.
And 525 at Wal Mart is about $23. 100 9mm is about the same.
Bad mix of hoarding and new gun buyers in the market now. I am guilty of it as well. Not to hoard, but its so hard to find now that I keep more on hand than I normally would. I used to keep 300-500 rounds of 9mm. My wife and I could shoot a couple hundred rounds in a weekend, then replace what we shot that day. It might take months to find 9mm now at regular prices (and I refuse to pay the higher prices whenever possible), so instead of the 300-500, I keep 1000-1500 rounds on hand.
Same with 22LR - used to be able to go out and buy a box when needed. Now its so hard to find, I keep 2-3 boxes on hand. Sometimes I cant even find shells for my shotgun.