Any Seat Award, then "pay for change"...?

[Deen]

Anyone have experience with this method of "upgrading" class by booking an economy ASA with points and pay, and then changing the booking if a PE or J seat becomes available?? then just paying the cash change fee.

Are the fees to change set or do they fluctuate depending on the price of the higher class seat?

 

[Happy Trails]

I've done this a few times from 'U' to 'P' with no problems.
And yes, the price will change, usually upwards, as supply diminishes so grab them while you can if the price is right.