如果由Rome -- Florence -- Venice-- Milan ，搭火車應該先買定pss嗎？

如果你只去這 4 個城市, 請忘記火車證這東西, 為什麼 ???

以上 3 程火車, 就算搭晒最貴的 eurostar italia, 總共都只是 130 - 140 euro. 如果你買 3 天的意大利火車證, 都要 121 euro, 仲未計留位費. 如果你分開買, 唔坐 eurostar italia, 坐 EC 或 IC, 更只需大約 90 - 100 euro 就可完成 3 程火車. 仲平過買 pass. 因此你大可去到意大利再買車票
你可能會問, "會唔會 full 晒???" 這 4 個城市是意大利的命脈, 真係點點鐘真車出發, 唔會一日 10 幾班車都 full 晒既, 10 點搭唔到, 咪 11 點 lor... 基本上你只要到達當地後馬上買票, 就沒有問題. 例如到達羅馬後, 馬上到車站買 2 天後出發去佛羅倫斯的車票. 這樣就已經好安全.
列車時間, 在意大利先決定啦, 點點鐘有車, 唔駛煩

I personally would suggest you to buy the tickets when you are there. I went to Italy last year, same route. From Rome to Florence, Venice, then Milan. I got train tickets just before I leave, usually the schedule for the trains are really frequent, so you don't really have to worry about the time and seats. I can only find one of my tickets which was from Venice to Milan, and the price was 20.66 euro per person, and it was just the normal class. For first class ( which includes meals) is not a lot more, but normal class is already pretty comfortable. This is Eurostar that I have taken. One thing you have to be careful is the name for the station. For Venice, the train station is called " Venezia S. Lucia" and Milan is called " Milano Centrale", you might get confused to similar names.
Also, the train tickets are not expensive.. soo I don't think a pass is nescessary.. Anyways have fun in your trip..