The $30 renewal is optional. Also what you are paying for is a high end bulletin board system that can run on most (if not all!) servers out there that support PHP and mySQL.
You must realize that there is a huge support team for vBulletin, Try comparing that to the support you get from a game
Also, You can add "hacks" to your vBulletin for FREE that will be very useful both to you and your members.
c'mon, $160 for a product that you can use until you die isn't a bad price at all! - Probably less than $3 a year
And once you have completed a game you can't do much else with it apart from playing again from scratch...but that would probably get boring after a while
Regards,
John Round
Webmaster, WeakestLinkForum.com