Online I’m seeing .223 brass jacket plinking ammo for around .79 cent a round in bulk.
Steel jacket even cheaper but I refuse to run that in my AR.
This search will show all the new ammo deals. There are a few 5.56 for ~.50 cents a round
https://www.reddit.com/r/gundeals/search?q=flair%3Aammo&restrict_sr=on&sort=new&t=all