Brian Steinberg Senior TV EditorCNN and Fox News Channel are fierce rivals, and their anchors regularly take pot shots at each other. But there is at least one thing on which they agree: how much a new subscriber to their streaming outlets ought to pay.CNN will charge $5.99 per month for its new CNN Plus, a subscription-video streaming outlet that is expected to launch in late March, according to a person familiar with the matter, confirming information previously reported by The Los Angeles Times. That is the same monthly fee sought by Fox News for its Fox Nation outlet.