I have been to a few games that tickets were running $100 or more, but most were Florida, Bama, or Auburn games. But most of the time, even if on a budget, you can get the tickets for a better price at the game than u can on eBay and/or other ticket sellers. You just have to be patient to get the bargains. Don't be afraid to make a much lower offer than the scalper is asking and you will be pleasantly surprised sometimes by the counter-offer. The only problems you may have are getting large numbers of seats together. A single ticket is easier to get than two together, 2 easier than 4, etc. No matter what, if you plan on going to multiple games, you will on average be able to buy tickets cheaper at the game. If you want a bargain, go to an away game. Foe example, when Peyton was playing, I bought tickets to see UCLA in the Rose Bowl for $10 bucks apiece, Arkansas in Fayettville for $20 bucks apiece, Georgia in Athens(IMO, Peyton's best game while at UT) for $25 each, and Bama(41-14) for $45 each, and bought em all at the game.
Don't let this stop you from asking everyone you meet, putting up notices you will buy tickets, etc., cause you can get alot of deals that way, too. Just be patient most of the time.