Just thinking outside the box....wondering if it might be cost effective to fly into Phoneix or LAX and rent a car there and drive to Vegas. Sure it adds an extra 8 hours of driving but you can make that interesting with pit stops in Laughlin or Hollywood or something.
Likely gas money would eat into whatever savings you get from the rental price (if any) but then again Vegas taxes and base rates are insane so maybe not.
Going to play around a little and see how the math works out.....