That doesn't mean you have to be unreasonable. Behaving appropriately during pirating is important since a ridiculous demand such like 15 million credits will hardly get anyone to pay you. The same with expensive cargo. If you're pirating you should also try to think of the trader and imagine what it would be like if you were in his shoes. This isn't the cruel RL world after all, people -can- be reasonable.
But if you instead intend to be greedy and give the impression that you only pirate because you're too lazy to trade yourself? you're in for a disappointment. Consider fair play. If I was given the choice between dropping half of my gold ore to a fighter or even destroyer with my 5k transport I'd show him the middle finger -every- single time. And that's hardly profitable for either side if you think about it.
