“The remaining 149 wartime detainees vary greatly, from prisoners the United States government has little interest in continuing to detain to a handful of the most notorious terrorist suspects of the era. In general, they can be divided into two groups: 79 lower-level prisoners who have been recommended for transfer, and 70 higher-level prisoners who have not.”* The Young Turks host Cenk Uygur breaks it down.

Taxpayers are spending about $443 million to operate the Guantánamo prison this year, or nearly $3 million for each of the 149 prisoners. Because many costs are fixed, once the low-level detainees are transferred, the per-inmate cost of housing the remaining ones at the remote naval base would soar even higher. By comparison, the federal Bureau of Prisons — which imprisons many convicted terrorists — spent $30,280 a year per maximum-security inmate in 2013. The Bureau of Prisons figure is not quite comparable because, for example, it does not include the cost of the federal court system, whereas the Guantánamo figure includes military commissions.

*Read more here from Charlie Savage / NY Times:
http://www.nytimes.com/interactive/2014/08/31/us/guantanamo-closing-qa.html