Please take just a second new folks, and look over a page or two of the forum before postin' about somethin' that already has a thread!
That said... If you wait until you have your tickets in hand to sell them you won't have much time. I believe they start sendin' 'em out some two weeks before the festival begins. So if you decided to try and sell your ticket(s) now you'd need to be clear with buyer that you will ship them as soon as they are received by you. Where you choose to attempt to resell the ticket(s) is up to you. There are plenty of ticket resellers out there.