As an example, I found seats departing Phoenix PHX on Wednesday, February 13, returning from Las Vegas LAS on Saturday, February 16.
Other dates are also available for travel on Tuesdays, Wednesdays, and a few Saturdays from January through mid-June.
See our fare details for booking info. This is a Basic Economy fare, which still includes a normal carry-on bag plus a personal item. You can pay double the amount for a Main Cabin Economy fare and be able to choose a specific seat, but I don't think it's worth it for this short of a flight.
For more deals to Vegas, check out our Las Vegas (LAS) listings.
Need a room in Las Vegas? Here's what's available for the above dates on Hotelwatchdog.