Other than launching satellites, being able to get things into space for the lowest cost is about as relevant as being able to get things to the bottom of the ocean for the lowest cost.

It's never going to be cost effective to send anything back down the gravity well, which means that the only way Musk's plan leads anywhere is if he's able to bootstrap an entirely self contained, self perpetrating economy in space. That's not happening in five years.

Edit: and no, data centres in space are not the answer.