its $40 for non-members, $30 for members.
you should join if you think you'll do it a few times so it pays for itself.
$35 to join, and you get 1 yr subscription to grassroots motorsports magazine.
http://www.motorsportsne.com/
And besides saving 10 bux on each event, you will get member discounts for events from PDA and NASA since we are partners with them.