GUANTANAMO BAY NAVY BASE, Cuba -- Guards get combat pay, just like troops in Afghanistan, without the risk of being blown up. Some commanders get to bring their families to this war-on-terror deployment. And each captive gets $38.45 worth of food a day.

The Pentagon detention center that started out in January 2002 as a collection of crude open-air cells guarded by Marines in a muddy tent city is today arguably the most expensive prison on earth, costing taxpayers $800,000 annually for each of the 171 captives by Obama administration reckoning.

That’s more than 30 times the cost of keeping a captive on U.S. soil.

It’s still funded as an open-ended battlefield necessity, although the last prisoner arrived in March 2008. But it functions more like a gated community in an American suburb than a forward-operating base in one of Afghanistan’s violent provinces.

Congress, charged now with cutting $1.5 trillion from the budget by Christmas, provided $139 million to operate the center last year, and has made every effort to keep it open — even as a former deputy commander of the detention center calls it “expensive” and “inefficient.”

“It’s a slow-motion Berlin Airlift — that’s been going on for 10 years,” says retired Army Brig. Gen. Greg Zanetti, a West Point graduate who in 2008 was deputy commander at the detention center.

Both its location and temporary nature drive up costs, says Zanetti. While there, he wrote a secret study that compared the operation to Alcatraz, noting that Attorney General Robert F. Kennedy had closed it in 1963 because it was too expensive.

At Guantánamo, everything comes in by barge or aircraft “from paper clips to bulldozers,” Zanetti says, as well as the revolving guard force. Also, more recently, a massage chair for stressed-out prison camp staff.

Zanetti, now a Seattle-based money manager, was a financial advisor in civilian life before his New Mexico National Guard unit’s call-up to Guantánamo. He has never disputed that America needed the detention center after 9/11 but argues that today it deserves a cost-benefit analysis.

“What complicates the overall command further is you have the lawyers, interrogators and guards all operating under separate budgets and command structures,” he said. “It’s like combining the corporate cultures and budgets of Goldman, Apple and Coke. Business schools would have a field day dissecting the structure of Guantánamo.”

An examination of the expenses shows that now, with no strategy for meeting President Barack Obama’s Jan. 22, 2009 closure order, the military is preparing for the prison’s next decade. Spending is not just aimed at upgrades for the captive population, most in medium security confinement, but also for the revolving staff of 1,850 troops, linguists, intelligence analysts, federal agents and contract laborers.

Commanders are contracting for a new round of capital improvements, including $2 million worth of new computer equipment to grow storage space under a fast-track, noncompetitive contract with Dell recently posted on a government website. And that doesn’t include the un-networked laptops the prison provides captives taking a life skills class that includes a resume writing lesson, in case anyone gets to go home.

Meantime, the guard force commander is getting a new 3,000-3,500 square foot headquarters at the prison camps for what is predicted to cost less than $750,000, below the amount that needs Congress’ sign-off.