Keep checking EBAY. Clemson fans are selling them pretty low.
You could also make up a fake screen name (CUFan89, AndersonTiger, TigerPaw70, etc.) make some posts (so you aren't asking for tickets with just one or two posts) and ask for tickets on the Clemson board. Many are selling theirs for well below what you see on many ticket sites. Good luck!!
I bet there will be TONS of counterfeits being sold outside the GA Dome. Come with tickets if at all possible.