| Nonstop Flights: Austin to Cancun $164-$175 r/t [October-December] â American Airlines [08/18/2021 @ 6:35 PM CT] Price drop to $164-$175. Was $186-$228. More weekends available. American Airlines has round-trip flights from Austin (AUS) to Cancun (CUN) for $164-$175, NONSTOP. Flights October to December. Weekends available. Click for more details and booking links Nonstop Flights: Austin to Cancun $164-$175 r/t [October-December] â American Airlines . | 