They are currently $1 per disk, are reusable, and last a very long time.
It is likely they are still being manufactured, too.
Even if the price were to double, I suspect that someone with the skills to make this has a sufficiently well paying job that the price of a hundred disks per year would not be a problem.
> It is likely they are still being manufactured, too.
As far as I can tell, they are not.