AmmoDepot.com has silver bear ammo cheap.Academy has monarch .223 ammo but I have seen too many rifles with jammed cases in the chamber caused by the monarch ammo.Thread is probably going to be moved to the ammo section.
I've previously found cheapest pricing at ammoman.com . I really don't much like 55gr and prefer 62 gr for plinking. For competition we use 77 gr for short range (out to 300 yards). But now you're not talking cheap bulk anymore.
I have gone exclusively to reloads for everything but .22 - we have a weekly MG shoot and for the past almost two months I have shot nothing by my reloads. Worked up a nice batch of 75gr 5.56 for my brother's benchrest AR15 and he was holding a 4-5inch group at 550 yards, and it looks like it was hitting pretty hard even at that range. Bullet trace showed a reasonable amount of arc.
But yeah, I am done with commercial ammunition for most applications.