You won’t find any mention of the cost in this New York Times article. The Pentagon frowns on discussing costs, and most of the mainstream media seems all too happy to go along. If you dig a little, you can get at least a rough estimate.
According to the Congressional Research Service, it costs roughly $3.9 million per troop per year in Afghanistan. Meaning that keeping 9,800 troops there for another year should run about $38 billion (and change). Now, I’m certainly not a highly trained journalist like the people working at the New York Times, but that seems like a pretty important fact.