I have a three year old Hydrologix C02 regulator with needle valve and solenoid, which was never used, on Aquabid starting for $30.
http://www.aquabid.com/cgi-bin/auction/auction.cgi?planta&1111724374
http://www.aquabid.com/cgi-bin/auction/auction.cgi?planta&1111724374
