If you scroll the website have a look at this:
Rome limousine by Airport Connection Service offer 3 different ways to go to from Civitavecchia dock to your residence or hotel in Rome or viceversa:
BY LIMOUSINE at the cost of 120 Euros ( price is for 3 or 4 people )
BY MINIVAN at the cost of 150 Euros ( price is for 5 or 6 people )
BY MINIBUS at the cost of 170 Euros ( price is for 7 or 8 people )
BY PRIVATE COACH FOR LARGE GROUPS starting at 280 euros.
It's much more than 65 EUR as Civitavecchia is approx. 50 miles away from Rome.
Go and check the website of Costa Cruises.
How to reach the departure port
For cruise guests arriving in ROME by airplane there is a train transfer service from the Fiumicino airport to the Roma Termini train station. From here you can proceed to Civitavecchia by train. Alternatively, you can reach the port by taxi at a cost of approx. Euro 150. We recommend that you verify and agree upon the price with the driver in advance.
and if you start to google: you cannot get any transfer between airport and port less than 120 EUR.