If you can leave from HOU and get from DAL to DFW, WN has a $116 round trip. You could run the numbers and see what AS gateway is the best deal. Some suggestions are DEN, LAX, PHX in addition to DFW. One warning with that approach, though: if you end up traveling on two separate tickets and don't make your connection between ticket one and ticket two (or between two and one on the return), the airline that delayed you doesn't owe you anything in terms of rebooking.