The pirates should operate as the mafia:
extort some protection money from those greedy bastards known as merchants.
Then they could have the luxury to sail away to sun set without any bother of
being robbed.
250k to start and 50k/month and I won't touch your ship.
10M/year, and I you can name a harbor and I won't touch any ships with that
harbor designation.
Of course, if I'm attacked, that'd opt the attacking ship out of the deal.