| Cheap Flights: Austin to/from San Juan, Puerto Rico $208-$225 r/t [August-October] â JetBlue JetBlue has round-trip flights from Austin (AUS) to San Juan (SJU) for $208-$225 with a connection. Flights August to October. Very few weekends available. Origin/Destination reversible. Click for more details and booking links Cheap Flights: Austin to/from San Juan, Puerto Rico $208-$225 r/t [August-October] â JetBlue . | 