We find they are all over the map. I book Buf to MCO or TPA. We are going in December around 25 to 28 and returning on Jan 4th or 5th. We are a little flexible because we own a timeshare, and I have booked Dec 23rd to Jan 5th, so I can take and add a day if need be, but because we are going again in March, I know that if I book and it drops, I can get the credit to use in March. That being said, I have done the last 4 years at Christmas, and last year the 3rd, 4th and 5th of January last year ran at $79 a few times, so I won't be booking that flight unless it comes out at $79. because I believe it will drop to around the $80 mark. Going down, I am booking when I see it get to where I am comfortable, around $140 to $170 so if it comes out that low, I will book it. I have $45 credit I can use on the way down, from a March trip that I booked in Jan. So I will use that credit for my flight down, but won't use for flight home as it's after the 1 year date. Hoping for good prices, but I have notoriously seen them drop between Sept/Oct. for Christmas.
March this year, there was never a good drop and paid more then I usually do. But I stalked the site like a crazy person, and ended up with $132 down, (only 1 flight that dropped to that price) and that is where I got the credit for. They were all over the map. I check JetBlue as well, they are only open to Jan 3rd, but I have already seen them drop some. $209 down and $150 ish home. Do what you feel comfortable with.