Wuxia stories take place in a pre-industrial age, but not a premercantile age. Today, of course, weapons manufacturers make billions upon billions of dollars selling weaponry to national militaries and civilians alike.
That makes me wonder: could there be any organizations in wulin who made their fortunes selling weaponry to wulin warriors? Imagine getting a contract from Kunlun Sect or Mo Dong Sect to manufacture swords for their disciples to use. Such an organization would become wealthy and powerful in wulin. It would probably be more cost-effective than opening an escort service or other typical wulin business.