deelmakur is right - nobody in the front cabin is paying full fare. They've already paid it, on the flights that let them "earn" the miles they used to buy the up-front seats. Hey, guys, we don't get nothin' fer nothin'. When you use an upgrade, you've paid for the seat, and you should be treated accordingly. That's true whether you've followed the rules and called 24 hours, or 72 hours, in advance to confirm an upgrade, or whether you're upgraded at the gate (something I've experienced only once in many, many years of flying, and then it was at the gate agent's initiative, not my own).