Apparently there are quite a bunch of people who hang out at the bars prior to the game, then during kick off or even mid way through first quarter find the scalpers. Thats when you get good deals on tickets, perhaps face, perhaps less. Only thing is now you are missing all the opening stuff, rushing to a seat (probably going to miss the second portion of the first quarter), and of course you have to be willing to take a single seat in the middle of wherever. But if you want to go to a Hawks game for cheap, this probably your best bet.
I'm a STH and it's the same scalpers outside just about every game. They just like StubHub are a business. It does them no favors screwing over a random guy selling a fake, since they plan to be out there for just about every Seattle sports game MLB, Soccer and NFL.
Another best bet is, as soon as you find a scalper out there you like (basically didn't screw you over). Get his business card (yup!), and find him for future games.
Now the only issue with all the above though is...you again take a gamble, with any scalper, you COULD get completely screwed over. You also COULD not get tickets period (the guy won't go down that much or at all) or if the game is big enough perhaps all the scalpers really do sell out, and then you gotta find a bar with some space for you to catch the game on TV.
I went to the Super Bowl and there were supposedly people who did the above and got tickets for less than face value. BUT that's a major gamble they took, not one I was willing to take at least (I wasn't flying over without a ticket in hand).