Great find! I'd love to hear how you found the flight. I'm assuming it's through Washington?
We were booking for my wife to go down in September. AC had some GREAT rates through Montreal ($398.xx all in), but they only had one ticket at that price.. so her friend got it and when my wife went to book it was $580. We let it cool for a few days and today it was down to $460.xx, so we grabbed it. Anything around $400 is AWESOME. Around $500 is GOOD. Around $600 is iffy and $700 is try another date.