I think they should revamp the Exchange so that no item can be sold for more than three times it's established value.
Not that it really matters to me, if I want something I just go out and try to get it on my own. Or make do with something else.
Also, I'm not a greedy SOB so I always sell my extra, common stuff for half it's value and the fancy stuff is usually posted at least at a 20% discount.
I'm here to have fun, not make a pile of galactic credits.
I considered that but ultimately decided against it as a bad thing for the players. As I posted what I think should be done is a listing fee that is a percentage of the value listed. Then the person buying it would also pay a tax equal to the same percentage. Something like this would work well as a natural downward pressure devise.