here's what i do and i always get super cheap flights - go to
orbitz or
travelocity and find the cheapest flight... then go to
priceline and quote a price even cheaper than the ones you found - there's a good chance you'll get it.
When I was scheduling my trip to ireland, the cheapest ticket i found was like $400 - i went to priceline and just tried $200, $225, $250 (these were all rejected, haha) but they did accept my price of $289
