This would be a NPC resource trading outpost where you could possibly have one in every 50 solar systems.
You would also possibly have to think about adding another resource to the game. Like a game dollar $ for the buying and selling of resource's through the trading outpost.Plus the price of buying and selling the resource's would go up and down depending on shortage or surplus of a particular resource.
Buying the resource from the outpost the player would have to send transports to pickup the resource's bought.
Selling the resource's the player would have to transport the sold resource's to the outpost.
To making the $ a valuable resource in the game and to involve all players to the trading of resource's. Is to add a $ cost to build ship's. This would mean at the start of playing a server you would get a initial amount of $ resource to start with.After that you would need to start to trading resource's with your closest NPC trading outpost to obtain $ resource.