https://www.theguardian.com/technology/2017/sep/14/flying-us-iphone-x-cheaper-than-buying-europe-illegal-hmrc-vat

Yet HMRC’s rules are clear: you must pay VAT on your £390-plus US purchases when you fly home, which makes those big savings a lot less appealing

The price of the new iPhone X is so high in Europe that it’s led thousands to eye-up transatlantic flights to see if it’s cheaper to fly across the pond to buy it. And it is, even with the cost of the flight, but there’s a catch: you would become an international electronics smuggler in doing so.