This is one of the rare situations where a mileage award ticket makes perfect sense. If you have elite status, airlines often open up additional award ticket availability. I have redeemed 25k AA miles for coach award tix where the alternative is a walk-up coach fare of $1,000 or so one way.

Not enough miles for an award ticket? No elite status and the airline wants double miles for a rulebuster ticket? Buying full fare? WN is the best option for ALB-SEA, as Southwest sells last minute tickets for reasonable fares, at least when compared to other airlines.