I just buy them at the theater. None of the previous two events have been sold out (here at least). My problem is that the theaters that it's showing at are not the best theaters in the city, the one closest to me has floors so sticky they act as mouse and rat traps. The one on the other side of of town from me I haven't been to, but I'm not sure I really want to go on suck a long trek to see something I'll be seeing on my home theater.
I really wish it was playing at better theaters here, the last two were held in newer theaters with state of the art sound systems (even though the season 2 even was marred by a lousy or lazy sound tech).