For the most part, this show is now sold out. A few tickets keep popping up, here and there, but not many. More may be released on the day of the show, so if you need them, keep checking. Job well done, Mexico! (Thanks @jogelu and David)
Update (04/20/13): Okay, it's not sod out at all. Tickets still available, and in many different sections, including General A. Update: "Sold Out" again. Give it a few hours & it will probably change again.