Most useful comment I picked up yesterday at the annual NEPA conference here in Washington DC was from a senior UK publisher of business information.
“Americans don't get it when it comes to marketing products online to Europeans,” he said (very politely, BTW). “If you want us to buy, tell us how much your product costs in £'s (UK pounds) or € (Euros).”
Hmmm… makes total sense, doesn't it? Why expect a potential customer to go through the mental gyration of translating your USD's into local currency. It's easier to delete your offer – and move on.