Quilet and I are buying our tickets tomorrow from the Warfield box office on the way to Golden Gate Fields.
You can buy tickets from here ($30): http://www.ticketmaster.com/event/2C004624A08342C9?artistid=969212&majorcatid=10001&minorcatid=1
Or if you want to avoid the inconvenience fees that ticketmaster charges you can buy tickets at the Warfield Box Office:
To purchase advance tickets without service charge please visit The Warfield Box Office which is open on Sundays from 10am-4pm and on Warfield show nights once doors are open until the headliner goes on. A box office fee of $1.00 for cash and $2.00 for credit card sales will be applied to each ticket sold at The Warfield Box Office during any hours of operation.