Not a bad price.
Fiber Optic Cable Weight Calculator
https://gegcalculators.com/fiber-optic-cable-weight-calculator/
It depends on what it’s covered with. The fiber itself weighs almost nothing but is extremely fragile. I have a hard time seeing 10km of it surviving. And it’s pretty expensive.
Fiber also has distance limits depending on the type. Single mode, multi mode, etc. There’s only one type that can carry data that distance.
L