We are travelling on land for 2.5 weeks in Italy and then doing a cruise to Greece and Israel. If I purchased a SIM card with data at the Termini station when we get there for an unlocked iPhone 5 will the data plan I purchase work in Greece and Israel too? Does anyone know how much one GB of data would cost? We can add it onto our plan from our Canadian provider for $70 for one month and it covers all three countries. Thanks for your help!
Check these two plans designed for visitors with Vodafone or Tim, Italy's largest providers. Both are 30€.
Vodafone: http://www.vodafone.it/portal/Privati/Tariffe-e-Prodotti/Tariffe/Estero/Vodafone-Holiday-English
TIM: https://www.tim.it/tim-visitors-en
There is no roaming within the European Union, but there is with Israel. You would need to enable the passport plan, which deducts I think 3€ Per day of your SIM credit. So you would need to add some money to the SIM card so that you have sufficient credit before you leave italy. Just go to any tobacconist and give provider name and tel number.
If you need data more than voice minutes, TIM has more: 4Gb.