| Cheap Flights: Austin to/from San Jose, Costa Rica $234-$276 r/t [Aug-Oct] â Southwest Southwest has round-trip flights from Austin (AUS) to San Jose, Costa Rica (SJO) for $234-$276 with a connection. About $99-$177 each-way. Flights August to October. Mostly midweek. Origin/Destination reversible. Click for more details and booking links Cheap Flights: Austin to/from San Jose, Costa Rica $234-$276 r/t [Aug-Oct] â Southwest . | 