Talk to your local welding supply. An 80cf in a home shop should last you plenty. I just inquired myself for a second bottle for a new welder and an 80cf runs $200 plus the gas($45-65 for c25) in it around here. Shop around because gas prices can vary quite a bit. Most will also rent the bottle for a few dollars a month. I never saw a whole lot of purpose in that but it might be easier to get you started that way. You have to watch used bottles. Without any paperwork they won't know if it's somebody elses rental contract bottle or been swiped from somewhere. If they will take it they'll be looking for date codes to see if it needs re-cert at your expense. Most bottles I've had my hands on have had the co. name casted into the neck ring so they don't really make mistakes.
