Moments after saving hundreds of dollars on round-trip airfare from Atlanta to Los Angeles, Phillip Walden, 41, experienced mixed feelings about the bargain $39 Southwest Airlines flight. 'What sort of corners would they have to cut to make a profit on that low a fare?' Walden wondered aloud after completing the Expedia.com purchase. 'Would $39 from every passenger even cover the fuel?' For safety's sake, Walden resolved to buy the second-cheapest ticket available from now on. 