All right, let me rephrase. Don't trade because you need money. It will be a chore. Trade if your character needs money.
Take me for example. I have two chars at the moment. One of them has about 12 ships, not counting the shared ones he has access. For a lot of months I had a place to spend the money. I never felt I'd have to do it faster. And now that he does not feels to have more, the cash is just piling. If he'll get an idea that requires a different ship, he'll buy it. If he wont have enough money he'll work a bit more. Or wait.
The other one is a bum. He's happy if he gets his hand on a couple of TCDs.