After they announce the bands the price jumps way up. I think $150 after they announce the lineup. It's kind of the risk you take. But it's always good so it's not much of a risk. I'm trying to figure out why I never got that email.
Actually the prices will probably be over $200 once they announce the bands. Last year's special mailling list pre-order was for $55 tickets, $170-ish once tickets officially went on sale and $190 after they announced the lineup.
For the special $60 tickets, they only release 3,000 at that price and they sell out within a half hour. Tickets are limited to 2 per order. I was able to get them for $45 each for Lolla 2006.
Nearly every festival does it. Cornerstone tickets go on sale in August for the next year, months before the bands are announced. By the time the bands are announced, prices have already increased like 2-3 times.