I think there were two ways to lock in 2012 pricing for 2013:
(1) By making a timely deposit for 2013 in July as discussed above
(2) By purchasing FST seats on site at the "select a seat" event last November.
As far as all this hurry-up-and-pay stuff goes, it supports what I've cynically said awhile back about them only being as nice as they have to be. They were A-1 jerks a few years ago when they had the leverage over the fans, and only became such warm and fuzzy fan-friendly people when they lost that leverage and had to drastically lower prices among other things.
So, as soon as they have ONE hot item to sell (the ASG), it's "pay now, or else." It kind of takes the edge off wanting them to ever have a contender because once they do, it'll be right back to the 2009 policies of obscenely high pricing, highly restricted club access, no perks, etc.
But I suppose that's a discussion for another day.