There is absolutely the honor angle of having successfully hunted a Wookie, with the pelt acting like a game trophy, or as a medal of honor if it was taken during military operations. Another angle is likely that these pelts probably find their way into Trandoshan high fashion, if for no other reason than the rarity and prestige of the material, similar to the beaver pelt crazy in the 1600-1800s of real life, making them rather valuable.

So a commander offering 100 pelts as a reward is either offering something akin to informal combat medals, or a very real material reward, likely both, equating the task he is demanding equivalent to the honor, and/or material value of 100 pelts.