I think the best strategy for getting tickets at a reasonable price is to show up at the stadium on gameday with some cash and "work the room." At Heinz Field, I've generally found the game day market to be much more buyer friendly than the advance market.
Think about this, there's only about 7 teams that aren't (or don't claim to be) sold out for the season. That's not a lot of face value seats out there to be had at the box office. Some of its speculative (like buying a condo in vegas).
The bargain game this season is going to be at Oakland where tickets can be had for about $60 and up. You can consistently get in the gate at Jacksonville for about $100 per. At Heinz Field just about every game is consistently selling for more than $150. You're softest games are going to be New Orleans and Tampa Bay.
The prices are outrageous -- but the upside is it's actually much easier to find tickets in advance if you want them. I'm a huge fan, I don't have tickets, but I'd be tempted to sell 'em to every game this season since their getting 3x. I could get the flat screen and the HD service.