just got to a welding supply shop to get your cylinder and filled ... i just got my new welder yesterday and it was $140 for my cylinder and it was a 90 cubic foot ....then another $35 to have it filled....that size will run ya for a while and keep ya from having to make trips to fill it up constantly
i run my regulator around 20 cubic feet per hour normally. thats with indoor conditions. if im outside and there might be a little breeze i might crank it up to 25 cubic feet per hour. and i went ahead and bought a 150 cf bottle and to fill it up runs around 38 i think at airgas.
when welding thin metal does the gas adjustment make a difference if the welds will be hotter or not, i seem to keep burning through my sheetmetal, and i have my welder on the lowest setting, and gas is at about 20.