A lot of people ask me what the coverage is for Thermark / Cermark. This is because the material is not cheap. But it does the job and it does it a lot cheaper than some other methods so I guess in the grand scheme of things it is rather inexpensive.
Here is the Coverage Chart for the LM Material Spray

Here is the coverage chart for the LM material. Contact your local distributor for pricing so you can figure out the price. For example based on the price of a can of thermark the cost per sq inch is approx $0.15.