Inexpensive CO2 tank regulator?

[Keibatsu]

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.

 

[acidrain]

The Harbor Freight regulators will work with some altering:
They use a metering orifice (at the outlet) with a gauge that is calibrated to the orifice size to read in flow (ass backwards way of showing flow for welding).
They also come with two different inlet adapters, so...
Take the reg apart by unscrewing the body and removing the spring and diaphram.
Drill out the outlet opening to about 3/16"
Blow/clean out all the chips and re-assemble.
The inlet parts thread into the body and can be changed. See if you can adapt the inlet to accept a PB ASA. Keep in mind that room temp Co2 pressures are in the 850 psi range.

 

[MrFoodScientist]

I believe I've seen some used beverage regulators on ebay occasionally for around $25.