When TCU last played at SMU, in 2008, the final attendance was 30,923...just over 1,000 shy of a sell-out at SMU's Ford Stadium. Given the increased interest in both programs since that last meeting and the fact that it's Parent's Weekend at SMU, it's not hard to imagine that this game will be sold out by week's end. So waiting until game day to buy your tickets at the door will likely not be an option, and even dealing with will-call at Ford on the day of the game is a pain.
So go to SMU's athletic box office website, buy your tickets ASAP and choose the option to print them out at home. And thank me later for the tip.