At Texas A&M this is a normal practice. I thought this was odd at first, but it's common place. Students can sell their student ticket to anyone, some times for in excess of $100 if it's a big game. You will need a student ID to enter, but for $80 they will convert the ticket to a guest ticket (by placing a special sticker on it) and a student ID is no longer required. They will do this at the box office on the day of the game.