If you've never seen the show before, mezzanine is a great view. It's the middle level of the theater. The front of the Mezz is best - it overhangs at about the 9th row or something so you are close. Those tickets are still over $100, though, at least back to the middle of the Mezzanine. Back of the Mezzanine is still good, though, and better (to me, anyway) than back of the Orchestra. Those tickets should be less than $100, maybe 70-ish? Balcony front rows are surprisingly good, but don't go there if you have a heights issue.
I am not fond of the Orchestra unless you can score an aisle seat so you can lean out and see stuff. I've always had some bonehead in front of me blocking my view during the show when I have sat there.
If you want to go really cheap, look for partial view tickets...those are maybe $37? Try to get left side partial view, you miss too much of Billie Joe on the right side since he comes in on the right. It's not like you miss a ton, though, still excellent views. And I think most shows (although maybe not the weekends?) have student priced partial view seats also. You buy those day of show at the box office starting at 10am or so.
Not so much the money (although surely that helps too) as better roles. Joshua Henry, the original Favorite Son, left for a starring role in Scottsboro Boys, also on Broadway. It got great reviews, but not ticket sales and sadly closed in a really short time.
I imagine they do get tired of doing the same show night after night, too. It's not like a TV show, where it's different for each production. And, of course, I didn't mention that most of them have been rehearsing this whole thing since probably Spring of 2009. So, they have been living and breathing it for nearly two years now.