The unfortunate part is that you have to add at least $15 to the order to get your tickets. It's not the money that's bothering me, it's that the delivery of tix won't happen until either 9/6 or you pick them up at a Last Minute Stubhub Center. Neither sounds comforting. I guess NW doesn't deliver tickets to season ticket holders until right up close to that first game?
To answer your question though, there isn't much demand out there for Northwestern games outside of the big boys of the Big 10 coming. Small stadium, limited interest. Go look at their website, they sell some crazy package for the Ohio State and Michigan games where the minimum is upwards of $100. They figure if Ohio State and Michigan fans are going to take up half the stadium, you might as well make them pay for it.