I almost like that "expert" label, but than it means we have to live-up to our reputation. We like the FCO Hilton for the night before our flights back to the USA, but the place sure has expensive food (the buffet dinner can cost you $100). This hotel is actually connected to the airport by a long overhead connector that ends at an elevator right in front of the door to the hotel. Keep in mind it is a hike when you have luggage. Getting from that hotel to the port on the train is the cheapest option, but not easy. You have to take the long trek back into the airport where there is train station. You than take the train (Leonardo Express) into Rome (most suggest going to the main Termini
Station although there is a possibility of doing it via a smaller station) and than go make another trek between platforms and catch one of the trains (usually hourly) that would get you to Civitavecchia. Once you arrive at Civitavecchia, you can than make the 4 - 5 block trek to the port entrance where you catch a free shuttle bus to the ship. That entire process will probably take you as much as 3 hours because of gaps between the trains, long walks, etc. The other option is to arrange a car transfer/taxi the Hilton direct to the port (you can find some services on-line or your hotel can arrange it) but this is going to cost you somewhere in the $150 range. AS to the actual trains, the Leonardo Express takes about 30 - 40 mintues into Rome and the train from Rome to the port takes about an hour. I am not sure of the cost of the two trains, but the total should be about $30 per person. Make sure you always keep your luggage under your control since theft is not uncommon.