I am going to be in New York in a couple of weeks and tried to get a ticket to see Die Walküre at the Metropolitan Opera. Nothing. I even asked Sarah, and she said even she could not get in. I put my name on the waiting list. It's ok. I can see it in HD.
I remember watching operas from the wings and from standing room. I also recall a performance of Carmen that I watched from the overhead lighting. It was an excellent seat as I recall.
I was able to purchase a very nice seat to see Joyce DiDonato in Ariadne auf Naxos.
I could get in to see The Book of Mormon, but it would cost $300+.