The nearly decade-long program to develop and field two VC-25B Air Force One planes by Boeing [BA] has a price tag thus far of more than $4.2 billion, but the service estimates that the cost to modify the 747-8i formerly used by Qatar's emir to be used as a VC-25B bridge aircraft is less than $400 million. The estimate on the total cost of VC-25B through fiscal 2031 is nearly $5.7 billion. The Air Force is pegging delivery of the…