The Media Underground blog writes:
How exactly is it that SpaceX can do everything so cheaply? Well, it would seem from this recent interview with Elon Musk that there are a couple of reasons in particular. The first being that there’s a tendency for big aerospace companies to outsource everything to subcontractors who then, bizarrely, outsource work to other subcontractors who subsequently - in what seems to be little more than an utter bureaucratic shambles by this point - outsource to other subcontractors and so on and so forth... ad nauseum. As one commenter aptly points out at the foot of this Wired article: "One reason for all that expensively administered subcontracting is that it pleases exactly those committees [who control NASA's funding]. The large projects they favor can subcontract in many different districts, whose congressmen then have a good reason to vote for NASA's budget. This means the committee members need not trade away any more of their political capital to get the projects that support contractors in their districts."
In short, SpaceX don't engage in this subcontracting farce but do it all themselves from the bottom up.
Wired has a great interview with Elon Musk here.
Anywhere there is some form of ridiculous inefficiency, there is opportunity.