American Airlines, Delta, and United have round-trip flights from Dallas (DFW) to New York/Newark (LGA/JFK/EWR) for $146-$154, NONSTOP. Flights February, March, April, May, August, September, October, November, and December. Very few weekends available. Origin/Destination reversible. Holiday blackouts.
A Carry-on bag and also a personal item is allowed for free on American and Delta. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.