I just have never understood why the athletic department doesn't put stuff like this on sale via the website or through the bookstore.
Perhaps because they want to use these things as a carrot to dangle for folks to buy season tickets, come to games, etc. I think it's a pretty savvy move, personally.
If you notice the recent trend regarding the athletic dept's advertising, promotions, sales calls, etc...the #1 goal is butts in the seats. This may come at the expense of the "long distance" fan sometimes, but it's hard to argue that the strategy isn't working.