I will be looking at a used Vermont Castings Dutchwest wood insert tomorrow. A guy is asking $750 for it, used one season. is there anything any of the experienced users could tell me about this unit? will i need a full steel chimney liner? my chimney is lined with clay that is in good shape. what will it cost to have the chimney lined (if i have to) and the insert installed? thanks in advance for your response.