American Airlines and Southwest has round-trip flights from Austin (AUS) to San Diego or San Jose, California (SAN, SJC) for $131-$152, NONSTOP. Flights January to May. Extended weekends available. Origin/Destination reversible.
A Carry-on bag and also a personal item is allowed for free on American. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.
A carry-on bag and two checked bags are allowed for free on Southwest.