Don't freak out and spend $700 on tickets. Be patient and You will see prices fall as the fest gets closer. In fact, last year, prices settled within a hundred bucks of face a week or two prior to the fest. Watch the boards as there are always people selling at face who have friends who can't go and talk to your friends, there are plenty of opportunities to not over spend.
Meanwhile, here is some actual SALES data I pulled from Stubhub.