Unlike typical trade in UWO where you simply buy goods from market keepers for ducats, nanban trade requires you to deliver trade goods to East Asia in order to be able to obtain local East Asian goods in exchange.
The English merchant Peter Mundy estimated that Portuguese investment at Canton ascended to 1,500,000 silver taels or 1,000,000 Spanish reales. The Nanman ('Southern Barbarians'), also known as the Baiyue ('Hundred Yue'), were an East Asian indigenous people native to the Chinese heartland south of the Yangtze, as well as present-day Vietnam.