i just pulled up MCI-LAS 8/31-9/3
swa $306 rt
spirit $386 rt w/ one carry on purse, one checked bag, bigger seat ($110), leave at 6:30 am to LAS, 1:00 am to MCI. ok take away the $110 big seat fee, and you're at $276 with shitty flight times, shitty on board service. seems like a crap way to save $30 on your way to blow everything you have at the craps tables.
yeah it's anecdotal but my bigger point is that if you're pinching pennies to get to your vacation, maybe vacation isn't the best idea