All lines are pretty comparable in terms of cost for transfer. Princess was charging $70 per person one way ship to Rome Airport FUmicilli (sp?). If you are travelling light, and I mean light, you can take the train to termini then switch and take another train to airport. Hassle hassle. I would never do it again. We did it on the way to the ship and had loads of time. There are no elevators at the Civitavvechia station - stairs stairs stairs mega hassle if you have heavy suitcases. If you can get a cheap cab $100 euros for two people. Do it, but again, it is 1.5 hours from the ship to airport by cab and the hassle of traffice and everything else. We personally build the cost of these transfers now into our overall cruise cost. Cheers.