That's a terrible deal, as are most "roaming SIMs". You can get that much data for half that price from Three (UK) among several other European carriers. Three is particularly popular since their SIMs can be bought in advance off Amazon.com, but depending on where you start your trip there may be a better deal for sale locally. The only thing you don't get is voice calling back to the U.S. but you can get that for free from Google Voice.