Bar chart showing average domestic airfare in Q3 2024 among the 50 busiest U.S. airports. A domestic flight cost an average of $366 that quarter. The most expensive flights were from D.C.'s Dulles airport at $473, followed by John Wayne and San Francisco International, both in California. The least expensive flights originated from Ft. Lauderdale, Florida (FLL) at $252, followed by San Juan, Puerto Rico (SJU) and Orlando, Florida (MCO). The average price in Miami (MIA) was $318.