In past years I kicked myself for buying too early as the prices always seemed to get better with specials being released mid year. This being said I bought my tickets for a Nov 30 departure three weeks ago as I felt $1157 total per ticket was good enough for me to make the early purchase. I had a budget of around $2000 per ticket so was happy with the savings.
It is unlikely that there will be any great fares after the 8th Dec as this is when the high season starts for the Christmas period.