Just an FYI for people making it north of Atlanta.
I know some people use Beverage Control, or know a local welding shop, but I was hard pressed to find a 5lb refill for under $25 in my work area. Maybe I'm doing it wrong, but LHBS Beer Necessities (aka BrewDepot) will do a 5lb for $14. Maybe you're all getting an even better deal.
Personally, I won't buy their hops, but I do get grain and equipment from them, and will get my CO2 filled there until I find it cheaper.
10595 Old Alabama Road
Alpharetta, GA 30022-8276