I haven't done any serious trading since the big update, but I can tell you that it was possible to make enough credits to buy a battleship in a week or under if you were willing to put the effort in before the update.
The key was and probably still is, knowing which routes to run and more importantly WHEN to do them.
If you get on the server at the right time, it's almost dead player wise, so there are no or very very few pirates, so you can trade virtually unmolested.
