I don't know what the cost should be really but I would ask for a quote excluding the removal of the old headliner (You can easily do that).
I just bought a boat. The headliner is removed and the ceiling is bare fiberglass currently. Owner is giving me the new cloth. I am strongly leaning towards painting the ceiling with some nice wood trimmings. Just throwing it out there. I think the cloth headliners just soak up a lot of dirt and moisture over time. Not to mention the fire hazard.
1978 Gulfstar 50'
Clark Sailing Dinghy 10'