Good news for United frequent fliers.br The airline is buying 40 new Boeing 737-700 airplanes to replace some of the smaller, older planes operated by its regional carriers.br According to a price list on the Boeing (BA) web site, the average price for a 737-700 in 2015 was $80.6 million.br Based on that, United could be spending more than $3.2 billion for the new jets.br "Our customers have a preference for an improved travel experience, including first class seats, Economy Plus, and Wi-Fi.br These aircraft are an efficient way to meet those needs," said Gerry Laderman, United's acting chief financial officer.