If we can make it to Vancouver for about $500 that still leaves the task of find airfare from ANC-SEA or BLI or somewhere close on the return trip.
Anyone have any suggestions?
Amtrak is not particularly timely at times (multi-hour delays are not unheard of). I would HIGHLY recommend you spend the extra travel day in your final destination city, lest a problem with a freight train cost you your cruise.
ANC-SEA direct service is covered via Alaska and Continental. Them's your choices, unless Allegiant suddenly decides to start doing BLI-ANC service using MD-80s, or unless you want to do some weird routing through PHX on US air, and so on.
The other thing to keep in mind is if you're splitting your ANC-SEA return with SEA-whatever-RDU (DL through ATL, maybe?) on two airlines, if things go askew on the way to SEA, your second airline's not under any obligation to help out (meaning: you could get socked with fees or even walkup fares if you miss your flight).