I'm going to Milan early next year on vacation from USA and I was thinking about buying a temp plan from my mobile provider TMobile. I'm also considering getting a prepaid tourist sim from either TIM or Windtre. I was wondering what the benefits would be. My phone can use 2 Sims and I would appreciate a local italian number to set up a temporary WhatsApp account but other than that I'm not sure.
I have no idea about the activation fees but there are usually some form of activation fees regardless.
On the T-Mobile site it showed $180 a month for 5 GB of data usage for a month. I'm pretty sure you can find unlimited data usage for 30ish bucks in Italy.
Just get something that's prepaid. I think €20 gets you 40 GB ballpark. You also get the benefit of getting a local number so you can make phone calls locally without any charges. Cell phone providers in North America are scum. I'm in Canada and we probably pay the most for our mobile phone plans in the world.