Send the estimate back and have them get one that is only for the damage to the door. Tell them you will after approval pay directly to the auto repair shop. If you want them to get up to 3 estimates that is within your reason. Just a heads up though to reskin a door and paint it is between 800 and 1,000 dollars. Due to lawyers and people rights of entitlement you no longer have repairshops pound out a dent and mud it flat any more.
Art