Vis a vis cheaper ways in, CSC is pretty good at getting people in with the rush line. I appreciate that they still do it pretty low-tech – just show up a certain amount before curtain, put your name on a list, and wait it out. At a sold-out performance of Carmen Jones, I was the fifth or sixth on the list and the last to get a seat (about 10 seconds before curtain!).
Also I have to say I think this price is more than fair. I know $80 is no small sum, but this would be a stacked cast even on Broadway, and tickets for far lesser off-Broadway musicals regularly exceed $100 these days.