Southwest has round-trip flights from Austin (AUS) to Las Vegas (LAS) for $126, NONSTOP. $63 each-way. Flights May to June, mostly midweek. No weekends. Origin/Destination reversible.
Note: Frontier has one or two slightly cheaper flights available with inferior, fee encumbered fares that charge a $60 to $76 dollar fee to bring a bag. You’ll want to avoid Frontier unless you plan on packing extremely lightly and have rock-solid travel plans already. We don’t consider the Frontier fares to be worthwhile unless they go on sale for less than $55.
Note: You can find additional savings if you book your Flight+Hotel together as a package on Southwest Vacations.