I just got back from getting some prescriptions filled. I stopped at the only gun store around. He had plenty of ammo and at good prices.
I got 5 boxes of PMC .223 brass case, 55gr. fmjbt for $54 including tax.
I almost ordered two boxes last night from Cheaper Than Dirt, but after shipping it was just about what I paid for 5 boxes locally.
I would check every cartridge of PMC, I bought some xm855 and a third of them had corrosion to varying degrees. Look for black stuff (zinc) inside the boxes.