If you have only made a few sales in the previous 14 weeks, then it will indeed stay between 3.0% and 20.0%. However, for a team that has made, say, 15 sales in the last season, the sales tax might instead range from 4.5% to 30%.
So an average of one transaction per week is already daytrading, that evil type of destroying the game? How about frequently buying young trainees, giving them 1-2 skillups and selling? That can together with team rebuilding very easily lead to 15 transactions. Forbidded, unwanted, not mainstream?
Look, I am really stunned. The game is loosing users. Many (new) users find it too complicated and others feel that they have too little money for a long time.
Now you are making this a poll-democracy. Do you really think that games need to be perfectly balanced to be exiting or attractive? I do not think so. A lot in game spirit is dependant on finding short-cuts, tweaks, advantages etc. . This is certainly not limited to daytrading, it can be the superiority of a certain training regime, a play-off strategy or whatsoever. Make BB mainstream, find yourself very lonely very soon.
I more and more feel that BB wants to make the game "perfect" in a way, that nobody can complain, that some "bad guy with unjust strategy" outplayed them.
This is nice - but boring to dead.
Claimer: I do not mind daytrading. In a growing community it is not a major problem. I respect any effort and success made by other managers who find a smart way to win. I like a balanced game. Tweaks and bugs are part of a balanced game.
Disclaimer: I am not daytrading.