For about a year I picked up a 100rd pack of Federal 12ga for like $19.99 at Walmart every time I went. No idea if I'd ever shoot it (I don't shoot shotguns often) but it's nice to have 1K+ of 12ga around. Plus 00 buck too.
Last year I bought several boxes of .270 to check accuracy/consistency in a new hunting I had gotten. Used no more than 5 rounds from each box. So glad I did that since I cannot find any .270 any where around any more.
Geeeez, it doesn't matter what ammo you are looking for there is none to be had - or, it is supper expensive if you can find it.