It makes sense that this prohibits doubling an item's price briefly then putting it back down and advertising it as 50% off

But if I'm understanding, this also means:

1. If you decrease a price incrementally you can only advertise a smaller discount (€100 -> €50 is "50% off", whereas €100 -> €50 -> €40 in same period can only be "20% off" because now €50 is a prior price)

2. You cannot advertise brief regular sales, like if you want to offer 50% off on the last friday of a month, because the previous sale was too close (even though it's at full price 97% of the time)

Which seem like unintentded consequences. I think using something like 25th percentile price over the last 60 days may have made more sense.

Are they trying to outlaw deflation now? I don't understand what they're trying to regulate. I can sell my property for whatever price I choose, no?