A 3 UK SIM would be cheap to use, but only when roaming on 3 Italy, so you need to check coverage. New tariffs are 12 pence a minute for UK landlines and mobiles, or monthly add-on packages similar to the new contracts, such as 300 minutes and texts for £15, with 300 min free calls to other 3 UK phones. And roaming off network, 10p incoming 25p outgoing.