Switzerland and Italy train travel

From what you describe above, your train travel is really not significant in any one country. A multi-country pass is not really necessary. Are you arrving by plane in Venice or getting there by train from somewhere else? This would add to your train trips. Here are some thoughts. 1. Venice to the CT wil take about 5.5hrs. You will most likely route through Florence. Some runs go via Milan but most go through Florence. Full fare is 54.10Euro. If you are willing to lock in a specific train on a specific date, you can get non-refundable tickets for as low as 28Euro. 2. The CT to Interlaken Ost will take about 8.0-9.0hrs. The best route is CT/Milan/Spiez/Interlaken Ost. There may be addtional train changes at Dommodosola and/or Brig. 3. You won't need an Italy pass for this volume of train travel. You can do better with Point-to-Pont tickets. 4. If you will be doing a lot of train travel from Interlaken into the Lauterbrunnen Valley, you might consider a Swiss 1/2-fare card especially if you will be visiting the Jungfrau or Schilthorn. It costs 110CHF and is good every day for 30 days. If your train travel in the Interlaken area is minimal, point-to-point tickets will be less expensive. Note also that a Eurail pass only gets you a 25% fare discount from Interlaken Ost anywhere into the Lauterbrunnen Valley.
5. For your journey from Interlaken to Amsterdam, most runs will have you change trains in Basel and Paris. Your final train will be the Thalys train from Paris to Amsterdam. 9.5hrs. The Thalys train is one of the worst for supplemental fees on top of the cost of a pass (30E-50E). I believe the fee is higher if you don't have France on your pass. Very expensive. Alternatively, there are a couple of runs with 1 train change in Frankfurt. No hassle with Thalys. 6. Just take the time to explore the point-2-point tickets. You'll get better deals all the way through.

Thank you for your advice. Sounds like I will be better off on point to point tickets. Is it best to buy on trenitalia.com? I notice that the tickets from monterosso to milan have a super economy price of 9 CHF, but the price of milan to Spiez only has a base fare of 59 CHF...Do you know of a way to get that ticket at a lower price? Once in Interlaken,we plan to spend 4 full days hiking and taking trams and trains to explore the area. Is there a break even point to make the 1/2 fare swiss pass make sense? Also considering flying to Amsterdam. Do you think that would be more affordable on EasyJet? Thank you for helping me figure out these details before I start buying tickets.

To get the best fare from Milan to Spiez, look on Trenitalia for a " Smart" fare. Choose a train, and hit Continue. On the next page, you will see a " your fare" option. From the menu, choose SMART. It will be 19 euro. Look down the page under seating. Green button means the fare is available; red button means it is not. If not, go back to the menu and try SMART2, which will be 29 euros.

@ Lola, Thanks for the instructions. I have bought the monterosso to milan central, and now am trying to buy the SMART fare for Milan to Spiez. I got all the way to see the green available spot, and it looks like you can not have a ticketless ticket? Is is a problem to pick up from a self service station in Milan? I thought I read somewhere that you had to be in the country to do this, so may not work for me coming from Itlay into Switzerland? Please help me verify before I go forward with this purchase. Thank you, Michelle