No.
The system don't work.
If a trader can't make a profit he can't trade. If he can't trade he do nothing more than any other carreers do.
I really don't care for the prices, but If the game developers will allow traders in the game, so they must do something that allow the players to use the class.
Any class must be playable regardless of the will of the other players.
If a realm say that is forbiden to preach, and I as a priest start to spread the word of my gods, I will probably be arrested and banned, but I CAN preach.
As a trader I CAN'T trade anything if the lords don't agree. The class is useless.
You can still trade as well if you only trade between someone selling 10 gold/100 and buying at 10gold/100. That is STILL trading.
If you don't like it, you can rebel, or go to another realm. Nothing is stopping you. Just because your realm is making a ducal power play doesn't mean it happens everywhere.
Anything that uses only a single realm as an example cannot be proof that a system isn't working.
Edit: Here's an example of why this argument doesn't work: This could have happened just as easily under the old system. If every region set their regions to only sell food at 99 gold per 100 bushels and to only buy food at 1 gold/100 bushels, then trading isn't possible either. At least not in any way a trader wants to trade. Thus, the system hasn't change at all in terms of a coordinated government stopping traders from gaining profit. There is nothing wrong with that from an OOC perspective, as it is a legitimate IC powerplay.
