I am a recent victim of the new dynamic pricing for day of departure upgrades, being quoted a whooping €369 for a miserable 1.20h flight from CDG to BCN.
I paid €423 for a Y to J upgrade last time from YUL to CDG (night flight) with
Goldorak!
Ridiculous...
Upgrade price from CDG to BCN (Y to J) on 11/17/2017
Upgrade price from YUL to CDG (Y to J) on 05/29/2016