as I understand it medical insurance will pay for it and the government too I guess if the medicine works and if there are no better options, because this rare disease is life-threatening and so they kinda have to cover it if this is the cure. don't they? well that's how I understand it, anyway.
The alternative for these patients is LDL-apheresis, that costs about the same and is very demanding on the patient and health organizations. Think about very young patients with a bad and painful venous access.