The Carrefour/Champion SIM's also have a rate of 0.42 to Italy. They also currently have an offer of double credit for in store top ups, so that would reduce the rate to 0.21/min.
http://www.carrefour.gr/mobile_champ...age=14&lang=en
Frog also has a charge of 0.42/min to Italy.
MoMad costs 0.59/min to Italy but currently has an offer for double credit with each top up, making it 0.295/min.
You have lot's of options if the main thing you want is cheap calls to Italy.