二百两 is a historical measure word phrase meaning 'two hundred taels' (a tael being a Chinese unit of weight for silver, roughly 37.5 grams). It appears in classical literature, historical dramas, and idioms to denote a specific sum of silver currency. In modern Chinese, it's used figuratively to mean 'a large sum of money' or in set phrases like 二百两银子 ('two hundred taels of silver'). The 两 here is the weight unit, not the number 'two'.