FWIW, I have not had good luck with AirGas here in VT. They really gear towards commercial accounts, so a local Joe like me would get charged an arm and a leg for a swap, and they don't offer to fill at all. I think they quoted me something crazy like $50 for a swap AND I had to use their tank. Luckily both LHBS's that are near me offer exchanges for $15-18, so I do that. I had to give up my shiny new tank tho, so I recommend making peace with that now...