Steeler tickets has been sold out since the early 70's. There is currently a minimal 15-20 year waiting list for season tickets, but as I said in the summer a few tickets for each game are made available to the general public. This isn't publicized. I found out through an email I receive since I am on the season ticket waiting list. Last year, I was shut out. This year I was lucky and scored 2 tickets to the Steelers Raiders game.
Some venues are very hard to come by. I didn't realize the OP was talking resale. Shoot if thats the case, $200.00 is cheap for resale.
I know this won't help you this year but are you sure that aren't a few set aside for public sale? Only way to know for sure is to talk to a real person in the ticket office and specifically ask. I know the Steeler front office doesn't offer up this info. It has to be specifically asked.