Well, by applying full localization you in effect create a second portal. However in reality NBS works on portal ids for the product separation, so you'd still have a problem of not having the correct currency in the product.
If you really need to do this, then currently your only safe option would be to create a second portal with it's own set of products, prices and currency.
If you really need to do this, then currently your only safe option would be to create a second portal with it's own set of products, prices and currency.