I am in the process of considering buying a 15 year old 6 burner Wolf from someone. I have found someone to install it, however, service seems to be an issue. Also, is $675 too much to pay?? I know that I have to get new venting, and read somewhere about installing flashing on both sides of the range on the walls. Is the latter necessary? Would you install this in your home? Is it a good deal? H E L P !