| Nonstop Flights: Austin to/from Cancun $155 r/t [December-January] (No Holidays) â American Airlines / JetBlue American Airlines and JetBlue have round-trip flights from Austin (AUS) to Cancun (CUN) for $155, NONSTOP. Flights December to January. Very few weekends available. Origin/Destination reversible. Carry-on bag is allowed for free on American. Any JetBlue segments have a bag fee. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate. Click for more details and booking links Nonstop Flights: Austin to/from Cancun $155 r/t [December-January] (No Holidays) â American Airlines / JetBlue . | 