Alaska Airlines has round-trip flights from New York (JFK) to Portland, Oregon (PDX) for $197, NONSTOP. Flights January to March. Departures on Tuesday, Wednesday, and Saturday. Extended weekends available.
Some small OTAs on Skyscanner have this for as low as $187; which is cheaper than the airline. If you plan on booking there, beware of any site that charges a fee to cancel a ticket within the 24-hour “free” period. Use unknown booking sites at your own risk.
A Carry-on bag and also a personal item is allowed for free on Alaska Airlines. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.