I "bought" tanks i dunno, 25 years ago?
dont look at it as buying - look at it as a lifetime lease.
Back then, in early 80s, it was either $6 a month for lease or $180 for buying a set. Sure, right now the oxy tank looks "like a escapee from the Smithsonian", but hey, it's in the garage, not the living room.
All i do is bring em in and swap em out. take em out of the truck, leave them next to the warehouse door, walk over to office, They just look through the window to verify the size, cash me out, and meet me at the warehouse door, where they give me new ones.
sometimes the tanks have their name, sometimes they dont.
If you show up with tanks, they assume you own em. people who lease get monthly bills from them for their lease - totally seperate from the gas charges.
Thats how the local place does it. We have Airgas too, but i havent dealt with them. And TSC has moved in, and is a LOT closer (15 as opposed to 25miles). Next fill I will probably look into TSC, although I expect they'll be more expensive.