For those that are interested in the price, this link is interesting.
"One kilogram of exotic glass feedstock can be expected to produce from 3 to 7 kilometers of fibers in under an hour in microgravity, under optimized conditions. At a nominal cost of $88K/kg, the launch costs for the preform and spool (estimated to be 2 kg) combined with the landed costs for the filled spools would be approximately $176,000.
The current low-end market price for ZBLAN fibers is $150/meter. Therefore, even at today’s lowest market prices, a kilogram of ZBLAN launched to space could be sold on Earth for between $450,000 and $1,050,000.
However, the real value of microgravity will be in producing ZBLAN and other exotic fibers of exceptional quality. Today, these custom fibers are sold between $300/meter and $3,000/meter. At current market prices, a preform launched to a fiber manufacturing facility in orbit could yield from $900,000/kg to $21,000,000/kg."
https://sites.google.com/site/cmapproject/case-studies/exoti...