We always fly out of Logan and we usually go to WDW in December. We're going this year the first week of December actually.
Anyway, we book ASAP if the fare is anywhere around $200 because we like to get what we want and not worry about it being filled up. We like non-stop and specific times, like early in the morning etc...
We've paid $770. and $800. for 4 tickets. But last year (the end of January), I found out, right on this board, about an AA sale for the Fall. We were going the end of October so I ran over to AA.com, Orbitz.com, and Expedia.com and it was true! It was $100. round trip for any flight we wanted; any time and non-stop. I couldn't believe it! I was so lucky! I quickly booked it, after picking which website, and was VERY happy. We ended up going with Ortbiz.com because, for some reason, they were about $20. cheaper than the other websites or else I would have just booked it at Delta.com because when you book with the actual airline and the airfare happens to come down, they will give you vouchers for the difference. It's much harder to impossible to get a voucher for the difference at a travel website.
So basically, what I do is check here everyday to see if anyone mentions a sale, then I check Ortbiz.com, Expedia.com, and Travelocity.com. I also check Delta.com (because they have the most non-stops at the best prices) and AA.com.
It's very hard for me to wait for sales which, I believe, are around August or September for a December trip!
My window just opened up for being able to book (it's 330 days out at all the websites) but airfare is at $219 today. It's just a tad too early to book this even for me...I'll probably wait till next month and see where the airfare is at. I'll probably book anything under $200.
Hope this helps you out!