Expedia is showing all kinds of seats @ $233 to $243 on your travel dates. $472 is insanely high -- who "quoted" you that? (The only carrier at that price level right now is DL, connecting through SLC.) I usually think $300 is the reasonable ceiling on this route, and my wife just got a SEA-LAX-SEA web fare on the AS website for $167, so keep looking around.