We got our tickets at the half price ticket booth - they are generally available there for a discount but not half price. I think we saved about 30% or so. If you're interested in seeing the show but not dead set on it the half price booths can be the way to go. If it's a must see for you best to book in advance.

We bought ours the day of the show from the box office (last week). Were able to get the next-to-cheapest tickets--about $70 apiece.

A day or so later I stopped in to tix4tonight, just to be nosy and see if we could have gotten them cheaper there. The man I talked to said that occasionally they have WB tickets but they're usually not much cheaper than box office (like $60) because he's so popular.