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In the age of outrageous à la carte airline fees, budget carrier Southwest Airlines has announced a one-way fare sale that allows travelers to purchase tickets for the price other airlines charge for a checked bag.

According to a Southwest press release, the 72-hour “4th Quarter Sale” allows guests traveling 375 miles or less to grab tickets for just $25 one-way. For travel between 375 and 549 miles, the one-way fare is $50. For one-way travel between 550 and 999 miles, fares are $75. Any one-way flight that goes 1,000 miles will cost $100.

The fares will only be available through 11:59 p.m. PST October 29, 2009 for travel between December 2, 2009 and December 16, 2009 or between January 5, 2010 and February, 10 2010. Additional taxes, fees, and exclusions may apply.

Southwest has been a leader in the airfare wars since long before the recession began. In a press release by fare-watcher Tom Parsons of Bestfares.com, the airline fare expert said: “The last time Southwest Airlines offered airfares as low as $25 one-way was 13 years ago. This occurred during July 1996 for their 25th anniversary sale.”

According to USA Today, Southwest also saw great success when the airline offered a 48-hour fare sale in July, charging $30, $60 or $90 one-way for all its flights.

Kevin Krone, Southwest’s Vice President of Marketing, Sales and Distribution said: “These fares are so low; Customers can invent a reason to go!” The low fares are available for purchase on www.southwest.com or www.swabiz.com only.

AirTran also announced today that they will be engaging in the fare wars, offering sales on travel through February 10th. According to their press release, fares are cheapest for flights that leave on Tuesdays, Wednesdays and Saturdays. Sample one-way fares include Boston/Baltimore to Washington for $29 and Milwaukee to St. Louis for $44 (blackout dates include November 25, November 28 to 30, December 18 to 20, December 22 to 30 and January 2 to 3).

The New York Times also wrote of sales being offered by budget carrier JetBlue, including their new, nonstop flight from New York to Saint Lucia for a special price of $129 each way. This offer is available for travel between November 2 and February 9, 2010, but must be booked by Friday. JetBlue is also offering Caribbean fare sales for Aruba, Puerto Rico, and St. Maarten. Fares range from $29 to $139 each way if booked by Friday.

Each of these budget airlines have also avoided adding a $10 “miscellaneous” surcharge for holiday travel that Continental Airlines, Delta Air Lines, U.S. Airways, Northwest Airlines and American Airlines instituted for travel around the Thanksgiving and New Years Holidays.

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