Travel experts have tips for booking summer travel

Most airlines now sell those at half the price of a round trip.

Because of the quirks of pricing and scheduling, you might save money or get a more convenient itinerary by flying one airline out and another one on the return leg.

American, United and sometimes Delta often match the discounters' fares but without extra fees for things like carry-on bags.

Airlines typically offer a limited number of seats at the lowest price, and if you're buying four or five seats together you could get quoted a higher fare.