American Airlines and Delta have round-trip flights from Dallas (DFW) to Mexico City (MEX) for $275, NONSTOP. Flights April to May. Departures on Monday, Tuesday, and Wednesday.
A Carry-on bag and also a personal item is allowed for free on Delta. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.
Read More Nonstop Flights: Dallas to Mexico City $275 r/t [April-May] – American Airlines / Delta