Now !!!! We are also going in December-and I bought my tix 3 days ago. Got them for $201 r/t per person. Very happy with that price. I was just so afraid they would go higher if I didn't get them.
That being said, Jetblue is GREAT because if the fares go down at all, just call them and they'll give you a credit of the difference and put it right in your travel bank. You have a year to BOOK from that date !!!!! I've done it a bunch of times, and had OVER $300.00 !!!!!! in travel bank credits to use this past Wednesday !!!!!!!!!!!!!!
I am also insane in that I check the website at LEAST twice a day to see if rates have gone down. But, that's how I got so much $$$$$ in credits !!!!!!!!!
Good luck !!!!
Lisa