SpaceX intends to get costs down to about $10/kg to LEO using BFR, almost as cheap as long haul air cargo. That is 2-3 orders of magnitude improvement and changes a lot of calculations.
The next calculation is how LEO transfers affects the environment/climate over the long term, when you begin using it as much as long haul air cargo...
Not likely.
In this case, they say a km of fiber is worth $1 million+. A 125 micron fiber weighs about 32.4 grams per kilometer, which costs $55 on a Falcon 9. So 20,000x less than the sale price.
That's why you capture an asteroid or mine the Moon.
I'm imagining a giant spool of optic fibre made from lunar regolith being wound back to earth directly from the moon