Rick Steves Train Tickets

The simplest approach is not to buy tickets in advance. Wait until you get there. Is there a huge cost difference if you don't buy in advance?

You just wait til you get there to buy the train ticket. There are plenty of trains going that way all day that you can buy
And the ticket would be cheaper if you buy directly with Trenitalia
https://www.trenitalia.com/en.html

or Italotren https://www.italotreno.it/en

instead of Rail Europe.

Just backing up the others here as it's standard advice for arrival-day journeys: just buy your tickets when you get there. Chances are that any price difference between a base-priced ticket at the station and a fully exchangeable one purchased in advance is going to be minor anyway.

Just a note that the link on the RS site takes you to RailEurope, a third-party reseller of tickets, not a subsidiary of Rick Steves Europe. They have an arrangement for the link, but its not RS selling you the tickets.

The important part is no refund at all less than 3 days before the scheduled departure of the reserved train. On the faster trains that serve this route and other big cities of Italy, there is no ticket category that will reliably allow you to take a later train. A full-fare or base-fare ticket only allows an exchange within one hour after the departure of the scheduled train, and that ticket is the same price that you'll pay in the station.

A full-fare or base-fare ticket only allows an exchange within one
hour after the departure of the scheduled train, and that ticket is
the same price that you'll pay in the station.

Right, and good that Laura provided that detail. You can change a Trentialia base-priced ticket without penalty anytime BEFORE the departure of the train purchased but only up to an hour afterwards. From the Trenitalia site:

https://www.trenitalia.com/en/offers/the_base_ticket.html

Before departure you can change your Base ticket free of charge and
unlimited times; after departure, up to 1 hour, free of charge once at
train ticket office at the departure station only. If you bought your
ticket online you can change it in the customer area on this website.

So if your flight was delayed enough to miss that train by an hour, your tickets would not be changeable or refundable. That's why it's best to buy at the station after you arrive.

Thanks to all for your guidance to hold off on purchasing train tickets until we arrive in Rome. I was concerned that tickets would not be available. Sounds like buying same-day tickets (we need 3) will not be a problem? ItaliaRail already had a note that said "only 5 tickets remaining" for the time we would like to travel - maybe that is just marketing-talk.

....Is there a ticket category that will give me peace of mind that I will be able to take a later train if we have flight delays to Rome? .... Simple answer, NO !! As well stated by everyone up thread, simply buy the ticket when needed at the airport train station. It will not break the bank since the pricing does not follow the US airline ticket pricing scheme. In Italy there are three levels of ticket pricing -- Super Econ, Economy, and Base. The first two are discount tickets with limited availability and strict limits on refund/exchange. Base is the standard price available anytime with normal exchange until one hour after the train has left the station. Just buy the base ticket when you arrival.

PS ItaliaRail is a travel agency reselling train tickets and not a train company. They may have only five tickets left to sell. Use trenitalia.com. They are the national rail company of Italy. There is roughly three to four trains an hour to Salerno so I don't think you will have any problems finding a train that fits your arrival.

ItaliaRail already had a note that said "only 5 tickets remaining" for
the time we would like to travel - maybe that is just marketing-talk.

They were probably just showing the amount of super-economy tickets left for purchase for that particular train. Those are the most inexpensive tickets, only so many of them are available, and they sell out the most quickly.

Just my guess, anyway.

It is "only 5 tickets remaining at that price". After that it is the next price level.

Newbies often need a lot of convincing that just turning up at the station and buying a ticket for the next train is normal behaviour. Business travellers do that all the time, and family emergencies, and 101 other reasons.

Would this advice of "wait until you get to the train station to buy the tickets" hold true for a train on Easter Monday? Or would you advise to book ahead online because it is a holiday?

Lynne, I know of one instance where trains were actually sold out, and it was not Easter Monday. It was a day in June, 2016, when someone I know had arrived in Rome planning to move on to Venice by train but every train was sold out due to some event in/near Venice. I had never heard of such a thing. She called me, in a panic (we lived in Rome then but were traveling elsewhere). They were at Stazione Termini with hundreds (her estimate) of other people in the same boat. They ended up with a 6 hour bus trip to Venice. 😱

I have since advised people who are worried about catching a high-speed train to buy the cheapest tickets they can for several hours after their arrival (like 4 or 5 hours later). Best case they get to use them. Worst case, they have to throw them away and buy full price tickets. Chances all trains are full? Unlikely but it happens,

Laurel - that's great advice, thank you! That's exactly what we will do. I was going to allow about 3-4 hours between arriving at airport & train time but maybe I will make it even later as you suggest.

They mean when you cancel you get 80% of the total price you pay for the ticket for the entire route. You cannot cancel one leg of the trip without canceling the entire trip. In other words, they charge a 20% cancellation penalty.

Don't us the resellers Italiarail and Raileurope. Buy from the train operators as noted above. Fiumicino Aeroporto to Salerno.