Describing SpaceX as a "startup" is debatable. The company clearly has a profitable business right now if they wanted to stop R&D and focus on launching satellites and Dragons to the ISS and making money, as they can undercut all other launch providers.According to The Wall Street Journal, SpaceX is valued at $12 billion. That makes it the 10th highest-valued startup in the world
Of course SpaceX will continue to put enormous sums of money into R&D towards their long term goal.