I have a masonry chimney and am getting an insert (avalon perfect fit). Liner is costing me about 500 bucks. What questions should I be asking to make sure I am not getting ripped off. Is there a minimum type of liner for this application that someone would install and charge a maximum price? I am buying from an established business that seems to have a great rep but I only trust myself so I gotta ask. Is the liner that would line a pre existing masonry chimney all the same? I am assuming that the new liner negates the chimney as the wood insert negates the fireplace. During the estimate the owner basically explained it like this. There is a new fireproof box being installed in an already fireproof box. Will the new liner follow the same principle? Thanks