The points scored for a commodity depend on supply and demand. Only those who strategize to manipulate the values of the goods will succeed in scoring enough to become a shipping tycoon.
The more you hit a shot for a particular commodity, the lower its point value will be. However, it will also raise the value of shots for the other commodities. When you cause demand for a particular commodity to fluctuate in the West, demand for that commodity will also move in the same direction in the East (though not by as much – the resources happen to be different varieties in the two markets), and vice versa.
The gauges in the center of the playfield track the relative value of shots associated with the different commodities. And once a resource has been collected and prepared for sale, the value of its delivery is also visible on the scoreboard. Watch how it increases as other commodities are collected, or decreases if you stockpile the same resource!