(sorry)

But yeah, I think having a marketplace area or areas would be a great idea. Focusing on the NT domain... if you obtained through a mission or through manufacturing or something weapons or engines better than the ones purchasable at the stations you can dock at, they can stock them up as cargo and cart them down to the marketplace in a couple trips. Set up a stall in-station, doubleclick a player and see a list of what they have and how much it will cost.

Since this one would be a legal marketplace, you would not be able to sell nation specials (although faction semispecials maybe) nor would the bailiffs allow you out with any equipment beyond what your licenses entitle you to equip (from your government) but it would be a good way to make money in conjunction with something like evoli's manufacturing idea until you are rich enough to own your own shop.