Another option is flying out of Midway on Southwest to Orange Co or Burbank airports all in for about $280 ea. So this a cash and miles thing you were thinking of? So if your cash outlay is $400 then the miles are only worth $700+ of the expense or as miles 3 round trips domestic. If you can afford it, buy the tix and if not then use the miles. Another option is to buy 2 tix with miles and two with cash. If you want to take a chance, you could put the dates on a watch on Travelocity or Hotwire.
My opinion only.