[05/24/2016 @ 1:52 PM] Old post clean-up. Fare gone. Removing from deal list.
Southwest has round-trip flights from Houston (HOU) to Las Vegas (LAS) for $198, NONSTOP. $99 each way. Flights April to May. Departures SUN-WED / Returns TUE-FRI. Saturday departures available for only +$20 more.
Note: You may be able to find a cheaper fare on a bare bones airline like Spirit or Frontier, but it will probably cost more if you factor in bag fees.