Ok, I am not high level so I could be wrong about this, but it seems to me that the player economy could get more and more messed up as time goes on.
High level players have nothing to buy in stores any more for the most part, and they keep gaining more and more money from doing missions and selling loot. The amount of money being held by high level players will keep going up endlessly, resulting in massive inflation of the cost of items that players sell to one another.
Also, they'll send some of their money downwards to lower level friends or secondary characters, resulting in the same thing happening at lower levels as well.
Is there anything to stop this from happening? And, will it be as big of a problem as it seems that it will be?