Someone recently posted a link to an article about this topic, I'm sorry I don't recall the specifics but I do recall the overview was varied opinions. How's that for being helpful
Kidding aside, there is a school of thought that feels the best deals occur closer to your planned departure, again, I'm sorry I don't remember but I'm thinking it was around 8-3 weeks prior to leaving. That was when they felt the airlines would offer the best deals to get the flights filled &/or TA's would offer discounted deals.
On the flip side, if said flights are filled and you wait too long, then due to basic supply & demand, you're going to see the fewer available seats rise in price.
Bottom line there's really no magical way to know. I can say from my personal experience, I start checking fares when I'm in the planning stages to get an idea of what it would cost if I booked today. Then I keep an eye on it for a couple days or even weeks to see if it moves up or down. Iwill check prices on both TA's and direct from the airlines, and before booking I'll even check with Disney to see if they can do even better.
Once I finalize my dates, when I see a flight that fits into what I feel is fair &/or on a flight or airline I want, then I book. I generally prefer to book direct with the airline because I feel I have more control over my reservation.
The hard part is once you take the plunge, if you book a non-transferable or changable fare, and the price drops, you feel like

but if the price increase, then it's
Good luck
