Sure, he overhypes, but already Falcon 9 is cheaper than all others and precisely because of reuse. I don't see how to deny this. Oh sure, SpaceX is a privately held corporation so we don't really know the real numbers and maybe he's just underpricing to convince the world he's right even though he's wrong, or something. But there's a reason ULA and others are getting into the reuse game, and it's that rocket engines are unbelievably expensive, so if you just reuse those you save a huge amount on costs. The evidence is overwhelming that reusing rocket engines is a huge savings. It must follow that reusing the whole launch vehicle would be a bigger savings.