I have lots to say about ammo prices and supply. Fortunately, everything I'd like to say (and much, much more) is said here. Go learn.
(The initial post, from Dave, is most relevant. I'm a little uncertain on some of the stuff from Kola. Commenters below are just speculating, like the guy who said that all rimfire ammo is made in Mexico. This is what we call "not true" or "wrong". Winchester's, for instance, is made in Arkansas, which is still north of the border, last I checked...)
(H/T to Porta's Cat.)