Exactly this. Go sign up for patio11's mailing list [1]. He just sent out an article to all his subscribers that talks about selling into Fortune 500 companies.

In all likelihood the manager doesn't want to have to go through corporate purchasing (or sole source). He wants to use his p-card, and that's his limit.

[1] http://www.kalzumeus.com/2012/05/31/can-i-get-your-email/