Even in Europe the difference is quite astonishing. A 32GB iPhone 5S in Ireland costs €799. In the US it is $649* or €480. In the case of a Mac, the difference will cover a return flight to the US.
*Without taxes, but as a tourist you can claim those back. Even taking into account taxes of both it's still a lot cheaper in the US.
Technically you are supposed to pay import tax into EU when the item is brand new, even if you bring it with you. And then the price difference between US and EU is not in your favour.
*Without taxes, but as a tourist you can claim those back. Even taking into account taxes of both it's still a lot cheaper in the US.