Fliying from IAH-AMS-BLQ and then on the return BLQ-CDG-IAH. Currently have just normal economy booked via miles, and looking to upgrade one of the long legs (IAH-AMS or CDG-IAH) to business, on miles.
Contacted Air France who told me that I would only be able to upgrade after check in, and didnt have an estimate on how much it would be. Does anyone have an idea on how much it would be, and if its possible to upgrade with miles/how much an upgrade with miles would be?