i know alot of people ask this but for me this is a little diff.

[Demobilized]

I would just suggest buying used from someone. You get a great deal and then would have cash for a tank, or extra money to play.

[mykroft]

My mag ran from 1994 to 2000 on a strict diet of CO2, without any replacement of o-rings or reg seats.

I've run it since then, but have replaced all the o-rings once.