The cost of taking a flight in the U.S. is starting to take off because of rising  oil prices  stemming from the  Iran war , which has already sharply boosted the cost of driving a car. A recent analysis of U.S. airline ticket prices by Deutsche Bank analysts found that average domestic airfares for travelers booking flights later this month have climbed by between 15% and 124%. The cost of a flight on discount carrier Spirit Airlines for late-March had jumped from $86 to $193, the analysis