Watch Stub Hub. Last Saturday they had tickets for $15 each, not terrible seats, about 30 minutes to an hour before game time.
I don't know this for a fact, but I have a hunch that the Athletic Department has been selling tickets on Stub Hub since it's become the official secondary market of UT tickets. Last year I got 3 together in the 3rd row of the upper deck South Endzone in a box for under $40 total for the Bama game. It requires some flexibility and can be a hassle to download and print, but it's worth it if you live in the local area.