There is no rhyme or reason as to when airlines "change" their pricing. If we knew, they wouldn't make money. But believe me, I try. I have a WDW trip planned April 2014 and I started looking at airfare early. At the time, it was in the mid to high $400's (from California to MCO). I thought the prices would go down since I started looking so early. They didn't. It continued to rise and not only that but connections and times changed too. I'm certain because I wrote it all down. Ended up going with a different airline because the one I was initially watching had terrible times, terrible connections and many connections via SFO which we avoid at all costs. The ones I was watching (via Denver and Phoenix) not even offered anymore. My rule of thumb for sure now, if I'm comfortable with the cost, I'll jump on it. Especially after learning my lesson this time around.