United Airlines have limited roundtrip airfare travelling from Phoenix (PHX) to New York / New Jersey (EWR) for $242 including taxes and fees. This is nonstop service.
Travel Availabiity:
Departs PHX: Feb 28; Mar 1; April 1, 2, 5; May 1, 6, 8, 9, 10, 16
Returns PHX: Good availabiliy March. April 4-23 is not available; then better in May and first half of June.
Book it on Expedia.
Sample itinerary attached.