Personally i like having my scuba tank. Its a 3500 PSI steel tank with a DIN reg. I bought it used for $110. Then I needed to buy the fill station which was a real pain($100). I know this is not why you are doing it but I like to have spare air for who ever needs it when I play. The way I figure it I pay ~ $8 to fill the tank or $6 to fill my HPA tank. I play with several people who dont have thier own equipment and I am trying to grow paintball in my area. So I will give the air away when my fill station arrives! Out of curiousity is the fire station a DIN hook up?? If so I bought my DIN to PB adapter from scuba.com. I thought it was a whip that you could hook directly up.