Fees to upgrade J to F
I have got CW seats LHR-ORD early next year using an AMEX 2-4-1 and have seen that there are now seats available in F on that day and the day before which were not available when I booked. We have never flown in F and the prospect is tempting. I know the amount of Avios required to upgrade but can anyone advise the approximate cost of the extra tax and fees? thanks