I know people here have said the show didn't have one but they have started a student rush for the show. It's on a show by show basis, first row (obstructed view) for, I think, $29. Just thought I'd pass it along.
When the box office opens, depending on availability. That's all I know. I didn't buy them because I wasn't so much into the obstructed view thing so I just bought a $39 seat.
For any interested, my TDF tickets tonight were in Row L of the Mezzanine on the left side. We could see everything easily and although there were a number of empty seats throughout the mezz, we didn't even switch (though I'm usually an aggressive seat changer).
I loved the show, but I'm a huge Christmas sap. Seeing it again in two weeks with my parents. Hope everyone enjoys it!