I agree with Bill from PA
Right now does not seem to be a good time to buy for December. Airlines are charging premium prices for the security of a flight booked long in advance. Except that there is no security -- many who buy now will see their flights cancelled and rebooked, at least once. That happened to me both for our Dec 2001 and Dec 2002 trips, and I only bought four months in advance! So why buy seven months in advance when the prices are high?