Since we have been asked several times, we researched airfares from a number of different cities as examples. Here they are (all rates in U$):
L.A.: 425
Seattle: 545
Denver: 566
Indianapolis: 662
Houston: 678
New York: 793
Boston: 799
Sydney, Australia: 843
London, UK: 870
Munich, Germany: 1217
So overall, there isn't a major difference to traveling to a conference in the states. Considering the great room rates we negotiated, this is going to be the cheapest trip to Hawaii you'll ever get!