Alaska Airlines and China Southern have round trip airfares travelling from Portland (PDX) to Phuket City Thailand (HKT) for $506, $523 or $534 (depending on the date you choose to travel).
Departs PDX: Jan 24; April 4, 11, 18, 25
Returns: A 1-week stay
Use dates and plug it into Priceline [priceline.com]
My sample below is for Jan 24-31, $506 showing different flight options but limited seats left.