Airgas has been charging me $35 to refill plus $5 hasmat fee. I'm going to stay with my 80 for mig but the tig uses a lot more gas and I don't think a $65 one time charge to upgrade to a 150 is all that horrible almost twice the gas will save trips, trip ... but a 336??? wow! I can't even pick up a 250 ... you would almost need a fork lift ... remind me not to arm wrestle with you lol.