I always go in this order when trying to get single tix
1) Hit up friends, alumni that would have direct tix from the school to see for extras (may sell at face value)
2) Stubhub or a site like it. Sometimes will pay more but dependable, stress free
3) If I strike out with 1, and the price is too much for 2, make sure to get around the stadium atleast 3-4 hours before and you should have zero problem scalping. If your there early enough can even shop around. I've bought tix before right near where the Vol Walk route would be and it's been easy.. if you wait that close before kick some sellers sometimes are willing to drop prices significantly just to get rid of them
Good luck! Be loud our boys will need it Saturday