Me and a buddy were going to every different station for trade prices, and here's one of the best ones we found (Read it all before doing it):

Start in Cambridge
Planet Cambridge - Gold for 543
Sell in New Berlin
Planet Berlin - Gold for 1,189
Buy in New Berlin
Planet Berlin - Diamonds for 396

Now, to get to New Tokyo, you're gonna have to go off the beaten path. In New Berlin, look for a gateway that will take you to Sigma 13 (I'm not going to say exactly where, figure it out for yourself). From Sigma 13 find a gateway to Honshu. Then from Honshu go to New Tokyo, and there you have it.

Sell in New Tokyo
Planet New Tokyo - Diamonds for 1,650
Buy in New Tokyo
Planet New Tokyo - Engine Components for 225

Now, a shortcut back to Cambridge. Take New Tokyo to Kyushu. Find a gateway in Kyushu to take you to either Tau 23 or Tau 29. From there, find another gateway to Tau 31, and then another gateway to Leeds. If you can find the 'mythical' gateway from Leeds to Cambridge then your set, otherwise, go through New London to Cambridge.
Sell in Cambridge
Planet Cambridge - Engine Components for 1275

Overall, you're making about 737, 500 per shipment if you do it with the humpback (250 cargo space). My buddy and I were running this with two humpbacks and making a ton of money, and there wasn't many problems with pirates either on these routes.


Hope that helps out for all of you traders out there