Norway has those taxes because they don't want to import agricultural products for a variety of reasons, not because the global economy is "encouraging" the US to sell our exports elsewhere and spread things "across the world". The analogy doesn't fit and the whole system doesn't make sense. Why would you want to work on goldsmithing, but have to go to a different city to buy goldsmithing items as opposed to where the abundance of supplies are?

What it sounds to me like you are saying is we should tax the location that has the most abundance, and then let people overcharge for things because they had to avoid the tax in one location and instead the players have to pony up the "convenience fee" that will be tacked on to cover the "travel costs" of selling where the lower tax is.

No matter how you slice it, it will not be good for the players nor the population in general. Heavy taxation is never the way to a healthy economy.