PayPal and American Express - A Poor Combination

So, last week I bought a battery grip on eBay from Germany for the princely sum of £65.  I paid via Paypal, for speed, convenience and security.  Now, my default funding method for my PayPal account is my (UK) American Express card.  Seems that Paypal have a stupid policy of always charging Amex cards in US Dollars - so that £65 was converted to $130.14, which Amex promptly converted back to £68.33!  So I'm out of pocket by £3.33 thanks to an utterly unneccessary back-and-forth currency conversion.  Needless to say, I've already changed my PayPal account to use a Visa card instead.  Grrr....