Prices do change over time. With 13 listings 39 days have passed.
a german national player get listed three times in a row, 2* times for 5,5 Mio and one time for 5 then he get sold for 6,5 after a bidding war. The question is, when 5,5 was overprized what could you sell about 6,5 as a selling price and two teams like to spend that.