Home Depot is already in the gas business. My local store has O2,
acetelyne, nitrogen, argon, CO2 and other gases. Prices are pretty
steep as you have to buy the first tank and then just do an exchange
and pay for the gas like with the propane exchange places. Gas prices
are 20-50% above either of the supply houses that I use normally, but
they sure do have them beat on open hours.

Craig C.