CI am currently running a pirate campaign. Long story short, my players are tasked with discovering the reason for the sudden dramatic rise in piracy along the sword coast and, if possible, stopping it by pretending to be pirates.

Using the rules from Ghost of Saltmarsh and some real world history, the party can attack ships and the like and sell stolen goods back at base. However, I'm at a loss when it comes to prices as well as what kinds of goods. I went with the common stuff, Tobacco, silks, spices, molasses,, but I want more variety. Since their ship can hold 100 tons, compared to cargo ships that can hold twice that, they'll be dealing with hundreds of pounds of goods.

Since I plan on allowing them to upgrade their ship (buy better cannons, special cannon ammo, hull and sail improvements, special rooms like a workshop or brewery on board, etc). I'm having a hard time finding a balance when it comes to price. since I don't want them to fully upgrade and be capable of bringing down a man o war without taking a scratch.

I was thinking along the lines of the following (in my world 100cp = 1sp, 100sp = 1gp, 100gp = 1pp)
Tobacco - 50sp per pound
Silks - 1.5 gp per pound
Spices - 1 gp per pound
Molasses - 2 per pound (for sugar and Rum making)