Q. Why do airlines charge more if you stay longer than 30 days? My husband and I are flying Lufthansa overseas this summer. My ticket is $566 more than my husband's, because he's staying just 3 weeks and I'm staying for 5 weeks. I would think to encourage tourism the price would decrease the longer you stay, but apparently not?

A. The airlines figure that casual vacationers who are just looking to go somewhere for a week or two, have more discretion in choosing where to vacation and thus need to be wooed with lower sale fares. Someone who's staying longer usually has a more compelling reason (such as work or a family visit), which makes them more willing to pay the higher fares.

Of course, there are exceptions! Just look at this Fare of the Day, which works out to be a real bargain for lengthy stays!