Do not be afraid to talk about the shortcomings. Agree that the transfer is an expensive service, but explain why the customer has to overpay.
tell them that, if they order a transfer, they won't have to run after children around the terminal after the exhausting flight while waiting for the car and then look for a car at the airport parking lot carrying heavy suitcases. On the contrary, the driver will meet the tourists, help them with luggage, and quickly and comfortably take them to the hotel.
Do not idealize the product as well, otherwise, the client will start looking for a catch.