Lockheed and Boeing are both very capable of building planes at scale, and in a competitive environment. Currently their space vehicles are built on a cost-plus model, but I think that L-B can adapt. Musk has an advantage today in cost, and should be able to maintain that for a few years, but don't think that Lockheed or Boeing can't compete once they realize that the gravy days are over.

It should be an exciting next decade for space travel. Maybe all the sci-fi I read will start to come true. Getting anything into space is a big challenge and hopefully soon the market will have several private companies competing in a real market for space travel. For a nice short story, look up "The man who sold the moon" by Robert Heinlein. Then we can discuss whether or not Elon Musk is the re-incarnation of the fictional character DD Harriman.