You can get the line for less than $100k here, but I’m not sure about the strength… alibaba.com/…/500m-Nylon-Fishing-Line-for-Freshwa…

This one would be $214k, advertises 36 kg of strength (.5mm diameter braided) alibaba.com/…/JOF-Japan-4-Brands-300M-500M_160105…

This one would be $3.5M, advertises 226 kg of strength (2 mm diameter braided) alibaba.com/…/Ashconfish-Braided-Fishing-Line-16-…