CupidBoy2, I thought I read that it went though 11:59pm Wednesday, and saw on their Twitter that it was extended through tomorrow at 9:30am. It's passed midnight (EST, at least) now but I searched a few minutes before.
It's possible they are all sold out though, I just wanted to make sure I wasn't missing something to search for the tickets in that price.
I checked the box office yesterday around 5:30, and according to the staff, they still had one open date, April 18th, with a handful of $19.75 tickets. Those were likely gone within a few minutes, given the length of the line.