A little advice with GeoLocating a website

Looking for some advice here, really not terribly Wappler related, just want you knowledge.

My client wants me to turn on Geolocation for their website, so on a standard page it should not make much difference as they are not trying to alter language or anything. On some pages though there are prices, so here is my question how do I convert a price from a base price set in UK Pound Sterling to US Dollars or Yen or whatever based upon what country the user is visiting from, and because exchange rate fluctuates constantly, how do i make my site get the rates from somewhere that tracks that.
Honestly do not quite know where to begin with this one.