I finally found a place online that claims to have case lots of .223 for sale.
It's not cheap but it's not out of sight, either. And the shipping is included in the price of the ammo.
Here is the
link.If you are desperate for AR magazines they supposedly have those
in stock, as well, but they are very pricey.
Crappy Russian 7.62 case lots at mediocre pricing but if you need them (and if they aren't lying about having them in stock) then
this is a solution.