So, if the NSA becomes aware of an exploit that they are able to procure for $ and they really have the security of the United States at heart don't you think the proper course of action would be to alert the vendor rather than to leave their own people just as wide open to attack as their enemies?

I could understand them hoarding their own research but this essentially confirms that the NSA doesn't care about the security of the home country as much as they care about being able to infiltrate elsewhere and to me that seems to be a badly chosen priority.

After all they can't know for sure who also has access to that vulnerability.