Exploit found: Unlike almost every other system, Thracia effectively has two super-city ports (Babylon and Byzantium), so if one of them ever has a shortage you can go to the other and ship the tens of thousands of goods it has in its open/military/black markets. It's much shorter (less than a day, as opposed to interstellar trade routes which take a week+) so are also much cheaper in terms of supply usage, to say nothing of the fact you don't need to burn a single drop of fuel since it's in-system. It effectively makes almost every other possible trade route obsolete while either of the two has a shortage. You can make hundreds of thousands of credits in real-world minutes, with nil risk.