According to today's Washington Post Travel section: Frontier Airlines has sale fares starting at $84 round trip, including taxes, from Washington Dulles to Charlotte, N.C., or St. Augustine, Fla. Travel through Dec. 17. Blackout dates apply, and sale does not cover flights on Fridays and Sundays. Seven-day advance purchase required. Other carriers are charging $241 round trip to Charlotte. Frontier is the sole carrier serving St. Augustine; other airlines are charging $297 to Jacksonville, Fla. Book by Oct. 6 at www.flyfrontier.com.