daystar:
I booked my fight through expedia.ca and got airfare for 3 from Buffalo, NY for about $450 US (including taxes and fees)... and then a few weeks later, I got airfare for my mom & her DBF to join us and she paid about $375 US for 2. I think I was checking the site at least once, but usually twice a day. I've read on these boards before that on a certain day of the week, the fares tend to drop, but I never quite figured out when... I just persisted (bordering on obsessed) and when I saw that low fare, I jumped on it.
My suggestion is to check often... sometimes the flights and fares seemed to change from morning to afternoon to evening. If you have the time and patience, just keep checking the sites and when you find something that fits your budget, grab it.
Hope you find a great fare and have a magical trip!