| Nonstop Flights: Austin to/from San Juan, Puerto Rico $210-$224 r/t [February] â American Airlines American Airlines has round-trip flights from Austin (AUS) to San Juan, Puerto Rico (SJU) for $210-$224, NONSTOP. Flights in February. No Thursday departures. Very few extended weekends available. Origin/Destination reversible. Click for more details and booking links Nonstop Flights: Austin to/from San Juan, Puerto Rico $210-$224 r/t [February] â American Airlines . | 