thank you for your question. It really depends on how much travel by train you think you may be doing during your stay in Italy. There are passes that you can purchase that give you up to 30 days or less of use. The best option would be to look at the cost of the trains that you think you may be taking and compare it to the price of a pass on sites like Eurail or Interrail. If you are not taking very many trains then it may be more cost effective to buy tickets. Passes will be more cost effective if you have a lot of travel planned, with a pass you only need to reserve seating on high speed trains and on regional trains the pass is your ticket so you do not need to purchase tickets.