Spirit has round-trip flights from Austin (AUS) to Fort Lauderdale (FLL) for $64, NONSTOP. Flights August to September. Departures on Monday, Tuesday, Wednesday, Thursday, and Saturday. Extended weekends available. Origin/Destination reversible.
Spirit fares do not include a free carry-on bag. Only a small personal item, like a Jansport SuperBreak backpack is free. You can avoid paying for seat selection if you accept the randomly assigned seat prior to boarding.