I found a very low fare on Travelocity by simply inputting my departure and return city without specific dates. It came up with a fare of only $214 ($280 or so with taxes). Travel dates are limited, though, so I am coming to Spain only for a week (I just got back from there 2 days ago, though!). But for that amount, I can't fly most places inside the states!
Anyway, once I find the fare, I always like to check directly with the airline to see if I can book the same flights/fare directly with them...sometimes you get better customer service if you want to change schedules or need info down the road. I was able to do so. The flight is with US Airways (with whom I have never flown), and I'm flying from Dallas DFW to Madrid, changing planes both ways (but with minimal layover) in Philadelphia. I think it's always trickier when you have specific dates you must travel. This was probably just a lucky find, but I hope this helps.
Also, try setting up your own FareWatcher on Travelocity. Other travel sites have similar things, but I've had best luck with this one. If you don't know, it allows you to input up to 5 destinations and will email you when the fares go down. I've found great fares this way in the past...still, the cheap fares usually require more flexible schedules and typically do not allow for changes. Best of luck.
Cara V. Hines<br />Texas, USA