Originally Posted by
flightrisk
I was able to re-create this fare with an even higher buy up. My guess is that it's caused by the JFK-PHX flight.
The JFK-PHX flights on 10/10 and 10/11 (Thursday and Friday before Columbus Day) seem to have extremely high pricing at 3-4x normal one way prices for all flights on those days.

Columbus Day is observed on Monday 10/14 and New York, unlike many other places, consistently recognizes and celebrates it with a day off. Maybe everyone is going to PHX for the weekend.