Good routes to make money selling stuff?

[Foxglove]

You can also trade Refugees from Kreuzberg Depot in New Berlin to Rochester Base in New York and take back Business Delegates from Planet Manhattan to Planet New Berlin.

Makes a bit less cash than what @"Operator SmileWhileAlive" proposed, but you don't spend time mining and you can do it alone. Watch out for police in Rheinland, though; they consider Refugees contraband.

Edit: Antonio ninja.

---