American Airlines has round-trip flights from Austin (AUS) to Honolulu, Costa Rica, Belize, Nassau Bahamas, or Cancun (HNL, SJO/LIR, BZE, NAS, CUN) for $263-$375 with a connection. Most flights are between August to December. Cancun fares are between July to December.
Cheapest fares are to Costa Rica at $263-$280.