Using the data:
"Primers are $28.
Powder is $21, makes about 500 rounds (or thereabouts).
Brass is free.
Bullets are ~$70/1k."
It comes out to $2.80/box of 20; but, there are some irregularities in the numbers. If you get 500 loads from a pound of power, then you're loading only 14-gr per round. Most folks load .223 Rems closer to 25-gr per round, which is about 280 loads per pound. Also, I suspect chris in va's prices are out of date and/or based on bulk quantity sales.
My LGS prices are in the neighborhood of:
Primers $4.00/100
Bullets $15.00/100
Powder $25.00/LB
This works out to over $5.50/box of 20.
Don't get me wrong, I'm a reloader; but, I try to be realistic about the costs. I think a lot of folks will agree, you don't save big bucks when reloading, you find yourself shooting more for the same money.
If you really want to save money, shoot handgun rounds with home cast bullets -- my 38 Special reloads are about $3.00/box of 50.