A point for consideration when pirating: If you ask for an exorbitant fee from the trader that results in them making no profit on that run, if they have any sense, they will then stop doing said run when you are around. This will reduce the number of encounters you get to have whilst playing that character, thus reducing your own enjoyment. Also, as the only ones that will be left passing you are the ones without any sense, you will end up only encountering traders that say "kill me, it's faster" or the like, which, again, reduces your margin of fun.
Sure, a pirate can be a nasty person, but this can be conveyed in the way in which they approach their demanding and the manner in which they communicate with the target. If you then go on to make a small demand, that will have no great impact on the trader's income, the trader may actively seek you out and want to be pirated by you, if only to get a good encounter and alleviate their own boredom.
There are a few pirates that I, personally, avoid, due to either ridiculous demands, or shoddy conversations...I'm gonna take every precaution possible to avoid an un-enjoyable encounter...