Are you running Nano tanks? Otherwise the cost of repeatedly refilling those paintball cylinders will cost a whole lot more than getting a real regulator. Also, paintball regulators are not known for their reliability. I have one 15# tank, with a splitter and two needle valves and I can run my CO2 24/7 on both tanks for 10 months. If they still have the one they listed on Craigslist maybe they will take a lower offer?