Pounds not nickles

I know some gateways do convert it for the customers.  Never used this feature at all.    I'm in the US and all prices are in US dollars on my site.  I don't have a pop up with an exchange rate, because that one may vary from card issuing company to another.  They all have their little build in fees.  I worry that if we show a converted rate that it may not be what later shows on the customers statement.  That can open a whole new can of worms.  Sometimes customers ask up front and I tell them to check www.xe.com to get an idea, but warn them that bank/conversion charges may apply.   As a customer I would always figure out what the exchange rate it by myself, if I order from another country.  I have done so in the past and expect a site to run in their own currency.   Most international customers on our site use paypal, because paypal shows them the converted price.   Never had a problem at all.
Katharina