I am considering adapting my paintball tank to a normal CO2 tank regulator, currently I am using a paintball regulator with some refrigerator tubing and a tire chuck at the end, I carbonate using 2 liter bottles with a cap that has a tire valve in it. The problem with this is it can waste a lot of CO2 from when I try to charge the bottle, the paintball regulator does not regulate much below 100psi, and I cannot accurately control the amount of CO2 I am charging with, I simply push the chuck to the tire valve for a split second and check if the bottle is firm. However I cannot seem to find a regulator for much less than $45, are they really all that expensive? I mean the paintball regulator I am using only cost $15. I will also need to get an adapter for the paintball tank to fit in the regulator, fortunately I have seen some online.