Rich,

I've been to AK about 30 times and have always flown Alaska Air since they are typically the least expensive. Lead time is one factor on the cost, the other 2 are the time of day you want to travel, and the day of the week you leave and come back on. Typically, Sundays, Thursdays and Fridays tend to be more costly.

I believe they even run a red-eye coming down to Seatac (saw one landing at 5 am one day when I was there). Not sure if that is cheaper or not.

Check fairs via one of the links posted above (I use Expedia) daily since they typically change fares about 3-4 times per day. The Kodiak leg is what kinda screws you since there isn't alot of competition for that route

Hope this helps a little,

Steve