have you tried any creative end-on-end tickets w/ partners?
i.e.
SNA/LAS $98 r/t on HP [1-day stay req.]
then
LAS/DFW $218 r/t on CO [2-day stay req.]
LAS/DFW $218 r/t on NW [1-day stay rep.]*
* permits routing via IAH, all on CO metal.
or, an all HP itinerary for $285.50