Frontier and Spirit have round-trip flights from Houston (IAH) to Las Vegas (LAS) for $77-$81, NONSTOP. Flights August to October. Departures mostly on Monday, Tuesday, Wednesday, and Sunday. Origin/Destination reversible.
Note: Frontier and Spirit fares do not include a free carry-on bag. Only a small personal item, like a Jansport City Scout backpack is free. You can avoid paying for seat selection if you accept the randomly assigned seat prior to boarding.
Note: Frontier and Spirit seats only have 28-inches of pitch; 2-to-3 inches less space than most other airlines.