I believe that is the motivation for the rumored change, to get more bang for the buck.  NASA does some great things with planetary probes, etc., but their manned launch systems have always consumed prodigious amounts of money.<p>For example, the money SpaceX has spent to almost complete the development of their new NASA-funded launch system is approximately 1/20 of the projected <i>cost</i> <i>overrun</i> of the internal manned launch system NASA has been working on (the Aries I).