i've had great success several times going to hong kong as a courier. you can do this from many major US cities. the cost is usually only a few hundred dollars, more during peak travel times and much less (sometimes free) if they have no one to go. unfortunately, you get to take only carry-on luggage on the outbound flight... but you can often check bags on the return flight.
there's often only one courier from a particular freight company on each flight, so you may not get to travel together with the other members of your family. and on some airlines, you no longer receive mileage credit for courier flights.
but it is something you may wish to consider, depending on the age of your son and how flexible his travel plans can be.
as for companies that do this... now voyager and IBC spring readily to mind; the others escape me at the moment.