As Niners Nation points out, this is a minor hurdle. These tickets are going to sell out fast, and the best chance will be through the secondary market. (They note that the Broncos are running a similar policy for their game against the New England Patriots.)
Of course, you could save yourself the money, watch the game at home where it isn't raining and you won't go through a ridiculously hostile experience with opposing fans. But hey, it's your money.
