How are people paired up? I realized this could be turned into a very interesting problem since the definition of international shipping is dependent on a person's location and there are groups of people for which a Secret Santa configuration do not exist. For example, a lone person in a country who refuses to ship internationally will not be able to send a gift to anyone. If Vic is going to be a nice guy, he will also minimize the need for international shipping.
Yeah know what, over the course of writing this post I think I figured it all out. There's one condition under which a group can't be made, and the number of people who have to ship international has a lower bound of the number of different countries. The upper bound of people who have to ship international is a little more interesting. Even better, how would Vic pick pairs to minimize the total shipping cost even within countries?