You must also factor in the 7.5 % tax on mileage purchases. (travelcodex.com)
It's worth noting that LifeMiles processes mileage purchases directly, meaning that buying miles with them qualifies as airfare spend. (onemileatatime.boardingarea.com)
You may have read about the ability to buy 100,000 US Airways miles for $ 1478 when they ran their 100 % mileage purchase promotion over the summer. (onlinetravelreview.com)