I just ordered my tickets in the upper level near the 50 yard line for only $15. Then the price just went down to $14 so can do this amazing deal too in sections 634 or 635. This is the OSU side (so I've been told).
http://www.ticketcity.com/college-football-tickets/big-12/oklahoma-state-cowboys-football-tickets/oklahoma-state-cowboys-vs-mississippi-state-bulldogs-texas-kickoff-classic-tickets-reliant-stadium-august-31-230pm.html
http://www.ticketcity.com/college-football-tickets/big-12/oklahoma-state-cowboys-football-tickets/oklahoma-state-cowboys-vs-mississippi-state-bulldogs-texas-kickoff-classic-tickets-reliant-stadium-august-31-230pm.html