Brokers don't have much interest in food, clothing, or electronics that are saturated with salt water. If the pirates escalate to bigger weapons, they're going to be letting water flow to the wrong side of the ship's hull, and the cargo will be worthless. I think forcing them to escalate to a shootout with a real navy is an excellent alternative compared with paying them for committing piracy.
Ships have value even with with bullet holes in them.
Even if a relatively large amount of damage is inflicted on the ship a substantial part of the cargo will be intact, esp. if fire is directed at the superstructure rather than the hull.
The problem is not intact cargo, but finding customers.
Also, if the pirates actually do shoot hell out of a merchant ship at long range, how many other merchants are going to continue resisting?