In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
The GB142 is only approved to be vented with 3" schedule 40,PVC pipe (Foam core cannot be used for the vent) . The use of stainless steel vent material is not approved. The PVC pipe can be run up to the top of the chimney and the fresh air can be taken from the room or the side wall.