> For now, Boring company uses the $50mm to subsidize their R&D cost as they move up the “learning curve” toward the realization of an order of magnitude in cost savings.

What makes the Boring company have the exclusive monopoly on R&D? There is billions of dollars available for R&D. If it was just a question of money anyone could idealize those cost savings. Your entire post is mere speculation. There is not a shred of actual fact based evidence to support anything you have said.