Paying for anything with Paypal in anything but your own currency will incur a Paypal exchange rate fee through their poor exchange rate. This isn't shown at checkout anywhere as Paypal just do the conversion and take a cut - about 3% - from any transaction payment conversion they do. Visa's exchange rate fee is 0- likely your bank's thus is BUT DO CHECK!
The trick is to make Paypal bill you in the original sale's currency and let your bank handle the conversion at market rate. To do this, go to https://www.paypal.com/uk/cgi-bin/webscr?cmd=_profile-merchant-pull-funding&buyer_hub
and click 'Conversion Options' next to your funding source. On the next page, change the selected option to 'Bill me in the currency listed on the seller's invoice' - don't worry about Paypal's scaremongering text about this, your bank/credit card likely handles this at market rates and doesn't add a further few percent for profit. Then just make your purchases knowing you'll be getting billed the exact market rate and not lining Paypal's pockets. Do make sure to check your bank's rate if any above the daily date.
Found via http://lifehacker.com/5957808/avoid-paypals-high-international-currency-exchange-rates-by-switching-one-little-option
Visa exchange rate: "Currencies fluctuate every day. The rate shown applies to transactions processed by Visa Europe on 31 August 2013 with a currency conversion fee of 0.00%."
***Do check your bank's fees*** (and post here so OP can be updated)
Visa Exchange Rate = zero additional fee
Credit cards = 0%
Debit cards = 2%
Credit cards: 2.95% transaction fee
Debit cards: 2.75% transaction fee