A couple weeks ago I got 1,000rds of .22lr for around $140(yes, expensive I know, but half of it was target match ammo).
I was able to land it by using this site:
I’ve gotten some sweet deals on AR mags by using that site as well. I also found the site to be a little fun, and fairly addictive as well. You will find yourself checking in on the mag and ammo markets constantly. LOL
I was checking in on stuff like that on slickguns.com but gave up eventually as it became a barren wasteland.