The majority of players in BB are experiencing super depreciation, inside players to an extent aren't even worth the effort to train in some cases. The supply has been increasing, dropping the value considerably. There is only one group of players whose value holds constant. And that one group of players are those who have what the majority don't. Uber skillsets with incredible secondaries. I've watched some transfers involving the cream of the crop BB players and their value still far exceeds their estimated value.
If you player ain't special, expect a low transfer fee.
Although I don't like it applied to my players, I can understand this is a sort of balancing mechanism to make market more stable (till next change....). Prices where simply crazy and much floating till two seasons ago, with high prices for triple 10 (all the rest 1) center. Problems are now two:
1) if you (I) paid a player some millions, you (I) don't like him to have 25% of his original price
2) if your financial system was designed to be sustained by sales income you are facing a tough time
However, if first point is boring, second is the relevant one, but if you have a self-sustained economy (no need to inject massive money to survive), you can have advantages, as what is relevant is not how much your players worth, but what you can do with that money.