The 5# are the ones that come with most basic kegging kits. I think they run about $80 but not sure. Mine came in a kegging kit , so I dont know what the cost breakdown was
got a line on a tank on ebay. just called an aquarium supply store and the guy there said its illegal to refill tanks in new york, they only swap them, and so buying a shiny new one is a waste. Any NY residents confirm or deny this, a local welding shop offered to refill a 5 pounder for like 17 bucks