Title text:
Detectives say the key to tracking down the source of the kites was a large wall map covered in thumbtacks and string. ‘It’s the first time that method has ever actually worked,’ said a spokesperson.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3121/
You can get the line for less than $100k here, but I’m not sure about the strength… https://www.alibaba.com/product-detail/500m-Nylon-Fishing-Line-for-Freshwater_1601256967845.html
This one would be $214k, advertises 36 kg of strength (.5mm diameter braided) https://www.alibaba.com/product-detail/JOF-Japan-4-Brands-300M-500M_1601056379751.html?selectedCarrierCode=SEMI_MANAGED_STANDARD%40%40STANDARD
This one would be $3.5M, advertises 226 kg of strength (2 mm diameter braided) https://www.alibaba.com/product-detail/Ashconfish-Braided-Fishing-Line-16-Strands_62225575567.html