Thanks for pointing me to EU 261 - super helpful. It looks like I was downgraded from class G to class Y. But I think you're saying they base the fare difference on what I paid for G in January vs what I would pay for Y today? Not what I would have paid for Y in Jan? If that's the case, it seems like pretty much any time they made last second downgrades, the passenger would be SOL, since fares skyrocket in price in the few days leading up to flights.