Or free if we managed to run solar powered sails (or so) skirting the very top and autonomously sending the harvest down.

If by “free” you mean “very very expensive” then i agree with you. It would cost a fortune to even just attempt a pilot project proving feasability. Then we would need to send up regular replacements to the “sending the harvest down” hardware at the minimum. Just imagining the cost of a tank which can be launched into space, autonomously dock with the collector sails, then deorbit and land makes my head spin. And then doing that at scale, paying people to launch it, paying people to operate the system.

It could be free if we imagine some crazy advances in autonomous self-replicating spacecrafts. But by then we live in the post-scarcity diamond age probably.