Can you give a little more detail please.
is there going to be a separate cost for each country? or 2 separate fess, one for inside the US and one for outside the US (or other country).
The best way to do this depends on the number of separate possibilities.
if there are only two separate possibilities, we will create 6 different rules, but if there are more, this becomes unwieldy, so we would store the rate in a session.