Best online place I've seen is $7/quart from myoilshop.com. A lot of people have reported decent shipping. I've heard of people getting it for $6.xx at places local to them, so someone in your area may be able to direct you.
Redline's website allows you to enter your zip code and search for the closest dealer. I know that Atlanta has several dealers including Summit Racing and BCI Warehouse. Redline will also provide a list of "by-mail" places if you want to comparision shop.
I'm in Athens, not far at all from you, and get mine from myoilshop.com at $7/quart + shipping, which was somewhere in the $8 range for a case of 12 qts. If you can find it at a store in Atlanta, though, that might cost less even if the price per qt. is a little more.
From what I've seen, not all dealers carry all grades. For example, neither myoilshop nor Jegs, nor Summit seem to carry 5W-20. If they do, they don't show it on their web sites. Luckily, I have a local dealer who sells it for $7.75/qt, and I save shipping. If you're interested in the web site, here it is:
Someone commented a couple weeks ago that myoilshop hasn't updated their page in a long time but carries the full line of Redline products. They said that they'd order 5w30 through the shopping cart and specify that they want 5w20 in the "notes" section. I'd want to call them to be sure, but the poster said they haven't had any problems doing it that way.