To build a fiber-optic cable connection costs between USD 10,000 per km up to USD 30,000 per km, including nodes and towers, and depending on natural geography. This is an expensive estimation considering the very cheap cost of fiber-optic nowadays.
If you want to know more, please go here. This data was sourced from the book Transportation and the Belt and Road Initiative, in which more data as well as the original primary sources of the data are available.
