Its very interesting how they get to use commercial flights to do landing tests. If 50 years from now rockets are reusable and there is competition, they'll be depending on the cost saving of reuse. Any new competitor will be at a significant disadvantage. It's development that is dirt cheap by todays standards, but will be considered expensive in the future.
How to do it will also be easier to learn about because it would presumably be done and published either openly or as a patent. People working in the field would know how to do it lowering the barrier to entry - hopefully making the high costs to study and research today pay dividends to the rocket industry. You are correct it would increase the cost to do similar research. Hopefully though the economy of the sector will be so much larger one off rearch focused launches can be easily done with the excess capital... At least that's my hope.
SpaceX does not file patents. [1] The assumption is that the protection offered by the patent is outweighed by the downside of giving your competitor a roadmap of how you did it. My guess is that just knowing it can be done will be a huge part of enabling someone else to develop similar technology.
