This means that British members, who mostly will have their own accounts use GBP, should tell their bank to do the whole transaction in EUR; in other words the conversion needs to take place on their end when the money is deducted from the member's account. That's why I'm interested how UK banks handle such transactions and in how far this results in (high?) fees for the UK bank customers.
My bank charge a fee for making the conversion, some percentage of the transaction amount. That's pretty standard practice here (in the uk) i think - akin to the charges for withdrawing cash whilst abroad or any other damn thing they can think of to make you pay to access your own money (grumbling noises)
Some big international sites will allow customers to choose what currency to pay in. But they ate big speciality shopping sites so i suppose they have that arranged with their accounts or built into the cost
It would be interesting how paypal deals with this - I never looked into it before but I will try to investigate before I make my christmas list for mummy!