Mr P, I rent 4 bottles 1 of each of these sizes K, Q, S, WQ rent is $36 a month Plus I own 3 s's and a q. For the big bottles of 100% argon it cost $78 to fill. For our "Norgas" its 75%-23% and it has a touch of oxygen and helium runs $63 for the big bottle. Oxygen in a q runs about $45 and the acetylene is about $38 to fill.