So recently purchased a flight through the Emirates website. Changing the price into Euros meant that Emirates added on £50, for whatever reason they had. One of the options was to pay with paypal, so I tried using that. I though that they would give me a better deal. Alas, it was not true. When paypal did the exchange, they charged me an extra £100.
You can see the details here, paypal thinks that 2096.66 Euros is equal to £1898.54. Whereas Google thinks overwise.