It all depends on, if you are providing colocation service you may expect local customers. If you are providing dedicated server plan, then you might get more from USA. This is just my suggestion.
Its very easy. If its the same currency they prefer it or even if its cheap. You jsut have to supply the different languages and get in their magazines and search engines...
Well my website is aimed towards USA not towards UK. I just get local clients via business network meetings and putting ads in magazines and newspapers. It says my phone number and nothing more on the ads, except my PO box. So they have no choice to get the USA prices...