Train Advice: Rail Pass vs Advance Purchase vs Day of Purchase

Seems to me you'll save a lot of money prebooking the trains now vs. the rail pass. The benefit of the rail pass is the flexibility to choose any available train you want last minute, if there are seats. I think even with the rail pass one must still buy reservations, though, if the train is reserved.

Rome to Pompeii by train means Rome to Naples and then the commuter train called the Circumvesuviana to get to and from Pompeii Scavi station from Naples. The high speed trains would be the ones between Rome and Naples, between Rome and Florence, and maybe part one train as part of the connections between Florence and CT and CT to Venice.

I've never felt it made sense to use a rail pass for Italy. You'd have to show me the math - which you can do yourself: figure out the last-minute ticket costs (full price) on all of these trains and compare that to the pass. Regional trains will cost the same in advance as last minute.

Please DO NOT a buy a rail pass for traveling within Italy.

You may want to read this very helpful website which will answer most of your questions: Seat61.com/Italy-trains

You can check train schedules on trenitalia.com

If you want to save money, you can book your freccia (high speed) train tickets up to 120 days in advance, but keep in mind that discounted tickets are unrefundable and unchangeable.

Enjoy your trip!

Don't buy a rail pass. Even with it you can not just jump on and take any seat on the high speed trains; you still need to make reservations which costs 3 to 10 euros depending on the train.

For the best savings book the following well in advance before you go and just print them out as a e-tickets.
Rome to Florence Rome to Pompeii (transfer in Naples)
Florence to Monterosso( Cinque Terre)
and
Cinque Terre to Venice

This way you have time to look at where and when you are going,

As others have said, don't buy a rail pass for Italy. Also, you may want to consider changing the order. A more logical order is Rome to CT, then CT to Florence, then Florence to Venice. Otherwise you are unnecessarily backtracking. Enjoy your trip!

A rail pass for what you intend to do would be a huge waste of money.
To make rail,passes worthwhile in Italy you have to be traveling on trains 24/7.
Buy point to point. If you are sure about travel plans, prepurchase economy or supereconomy tickets (which are non refundable and non changeable.

This is all very helpful, thank you! I'm going to review train info with your advice and will update once I have more info.

Rome to Pompeii by train means Rome to Naples and then the commuter
train called the Circumvesuviana to get to and from Pompeii Scavi
station from Naples.

Just to add, passes are not good on the Circumvesuviana, and you won't find the schedule on the Trenitalia website as it's a localized commuter. Current schedule is here:

To Pompeii/Sorrento (you want Pompei Scavi Villa dei Misteri station):
http://www.eavsrl.it/web/sites/default/files/eavferro/Napoli%20Sorrento.pdf

From Pompeii/Sorrento:
http://www.eavsrl.it/web/sites/default/files/eavferro/Sorrento%20Napoli.pdf

I'm not even sure these tickets are available to purchase in advance but they're very cheap and easily bought when you get to Naples.

Italo operates a private high-speed train system to major Italian cities, and has competitive rates so you might check their prices as well. They also do not accept passes.

https://www.italotreno.it/en

You can do the math using the full fares and reservation fees shown on our Italy page. Trains that are not covered are listed on the same page.

• Full fare tickets for your route (except the local Circumvesuviana between Naples and Pompeii) add up to about $255 per adult in 2nd class and include seat assignments where required (on most trains).
• A 4-day Eurail Italy pass with group discount currently costs $203 per adult in 2nd class, plus probably 5 seat reservations for $60. So you see that it's not saving money for this route, nor adding much hop-on flexibility.
• Advance-purchase tickets can reduce the $255 ticket estimate, if you're ready to lock in dates and times for one or more legs of the trip.

Thanks everyone! I've put below what we ended up purchasing just in case others want to know when searching in the future. I did appreciate the advice about the fact that we were backtracking a bit, but we had already booked our places to stay so we were locked in. I see now why that would have been a better way to do the trip because the train trip from Cinque Terre to Venice will be 6.5 hours which isn't ideal. You live and you learn!

We ended up purchasing a guided tour for the Pompeii day trip, just for convenience and fun so no train tickets there.

Booked 1st class Rome to Florence.

Booked regional from Florence to Cinque Terre-Riomaggiore

Booked regional and 1st class from Cinque Terre-Riomaggiore to Venice

All the train trips total for 2 people were $256.66 so I feel good about that, especially since some are first class. The train site that someone posted was awesome and I booked everything on italiarail.com which was very easy. Thanks again everyone!