The bargain bus fares -- $10 from Washington to New York City, $15 for a round trip -- seemed too good to be true.

And now they are.

Dragon Expressway & Travel Inc. and Washington-New York Express Tours, the Chinatown-to-Chinatown bus companies whose six-month price war offered good deals to thrifty travelers, have doubled their ticket prices. Fares on the Washington-New York route now begin at $20 for a one-way ride and $30 for a round trip, the companies say.

Dragon raised prices the day before Thanksgiving to temporarily capitalize on higher passenger traffic during the holiday weekend, said Kevin Ho, the bus line's New York manager. But this week the company jettisoned plans to drop the prices back. Rival Washington-New York Express also raised its ticket prices in the past week.

Both bus lines have lost money on the Washington-New York route since May, when the price war began, slashing the cost of a round-trip ticket from $40 to as low as $15. As word of the cheap tickets spread, ridership surged. But revenue never kept pace with the cost of the expanding service, which required new drivers, buses and insurance, local managers said.

"We need to make some profit, and with $10 and $15 tickets, that was not going to happen," Ho said. "We tried to start the business with these prices to attract customers, but they were always temporary." A manager for Washington-New York Express did not return phone calls yesterday, but a handwritten sign outside the bus line's Chinatown terminal notifies customers of the higher prices.