re: Why give the Saudis more when we already have our bases there?
Whether we like it or not, the Saudis are our allies there and we have vulnerable bases there. We need each other, and they have oil, and are ready to pay good hard cash, which we need, for these weapons.
Complicated long-term relationships like this are why we have a State Department. You need full-time professionals with extensive knowledge in the region to set up these alliances and to integrate them with national policy and interests. Over the last few years, much of this planning and decision making has been taken over by the White House, which has ideologically always been impatient with the pointy-headed intellectuals at Foggy Bottom.
That's why Colin Powell quit.