Anyone else having issues with the fares when making changes to a flight? Have two flights I need to change. The first one is booked in C+ and original ticket value is $486. Buying the flights I want would be $451. The change flights button is asking for an extra $160!! Second flight is booked in F with miles. The price for buying it new is the same as my original fare, yet it wants to charge me an additional 3,400 miles