Court-appointed lawyers for Savage and his codefendants have logged more than $3.3 million in fees and expenses - a record for a federal case in Philadelphia - and are still billing.
The defense total is a fraction of the prosecution cost, according to one expert. Government lawyers, FBI agents, and staff spent years building the case against Savage, at times working on nothing else.
The jury selection and murder-racketeering trial in Judge R. Barclay Surrick's courtroom lasted seven months.
The court shelled out $325,000 in per-diem payments and travel expenses for 1,100 prospective jurors and the 18 eventually picked for the trial, according to information compiled by court officials.
Juror lunches and snacks topped $24,000. Transcripts cost $249,000.
On most days, a half-dozen U.S. marshals ringed the courtroom and escorted the defendants, jurors, and witnesses. Additional security and travel costs exceeded $283,000, the Marshals Service said.
And the price of imprisoning Savage is at least $31,000 a year for each year he lives, prison officials say. That could be decades. Savage is 38.
"Frankly, no one should be surprised to see it cost this much," said Jon B. Gould, an American University law professor who has studied defense costs in federal capital cases. "If we're going to do it right, so that [death-penalty] convictions are accurate, it's going to cost money."
In his 2010 report to the U.S. Judicial Conference, Gould and a colleague, Lisa Greenman, found the median cost for one defendant in a capital case in 2004 was $465,000. The most expensive was $1.7 million per defendant.
Those numbers are likely higher now. Three years ago, death-penalty lawyers got an overdue raise - a 42 percent increase to $178 an hour. (Last month, the rate was cut to $163.)
In some ways, the Savage case was an anomaly. U.S. prosecutors in Philadelphia have sought the death penalty three other times since 1998, but never before convinced a jury.
It also reflects an increase in the last decade in federal capital cases, among the most complex to try. And it comes amid government budget woes.
"The substantial costs of death-penalty prosecutions should call into question once again the value of these prosecutions," said Leigh Skipper, chief federal defender in Philadelphia, whose office laid off five people this year.
Savage was already serving a 30-year term for a 2005 drug-trafficking conviction when prosecutors built the murder case. The 2009 indictment cited 12 deaths, but the centerpiece was the firebombing he ordered from prison. The victims were the mother, son, and relatives of Eugene Coleman, a former associate preparing to testify against Savage.
"He had never been held accountable for this," said Assistant U.S. Attorney David Troyer, the lead prosecutor. "There was no question that he needed to be held accountable."
Charged with Savage were his sister, Kidada, who helped plot the arson bombing; Robert Merritt Jr., an accused accomplice in the firebombing; and Steven Northington, a hitman for Savage in two other murders. All were eligible for the death penalty, though prosecutors ultimately decided not to seek it for Kidada Savage.
William Purpura, one of Kaboni Savage's lawyers, said the trial was inevitable because prosecutors wouldn't consider a plea deal for life in prison.
"The government's only offer in Kaboni Savage's case was death," he said.
Patricia Hartman, a spokeswoman for U.S. Attorney Zane D. Memeger, said the office would not confirm or deny any plea discussions. But during the trial, prosecutors argued that Savage deserved death because he had made it clear that he could - and would - orchestrate killings from prison.
Each defendant got two court-appointed lawyers, a typical practice for indigent capital defendants.
Christian Hoey, a defense lawyer from Paoli, led Savage's defense team. Surrick added Purpura, a Baltimore-area lawyer with experience in capital cases, last fall after Savage's first lawyer, Timothy Sullivan of Greenbelt, Md., withdrew to become a judge.
Choosing an out-of-town lawyer is not unusual in such cases. The Philadelphia federal defender's office has 15 trial attorneys, but none could represent Savage because the office had represented potential witnesses, cooperators, or other defendants - an unequivocal conflict.
In interviews, four of the eight court-appointed defense lawyers in the Savage trial said it was the most extensive and exhausting of their career, requiring 16-hour days and preventing them from taking any other clients.
"Other than just sleeping, you weren't doing anything else," said Will Spade, one of Merritt's lawyers, who had been approved for $378,000 in fees through mid-August. "I turned a lot of work away - I think every defense lawyer in the case did that."
The bulk of the fees - $1.2 million - went to Savage's lawyers. Hoey, who had worked the case since February 2010 and served as the lead trial lawyer, billed $589,000.
He said the case was like seven murder trials in one. When those ended, there was another trial - the penalty phase to determine whether Savage should die.
Defense lawyers also claimed $99,000 in case-related expenses through August. Purpura said nearly all of his were for his $3,000-a-month apartment at the Benjamin Franklin residences in Center City.
"There was seven months where I lived in Philadelphia, stayed away from my family," he said. "We hunkered down with this case from early-morning hours to late at night."
The vouchers outlining the expenses and fees are sealed under court policy.
The U.S. Attorney's Office said it would be impossible to determine how much it spent on the case.
Staffers often work several cases at the same time and don't keep logs or track travel costs for them or witnesses.
Gould said his research suggests prosecutions cost more than twice as much as capital defense. "They have to spend more - and they do," he said.
According to the FBI, the two investigators assigned to the Savage case spent six years working on it exclusively and an additional four years devoting half of their time to the investigation - a tally of more than $1 million even if both made less than six-figure salaries.
Troyer, a career prosecutor who said he long ago hit the $155,000 top of the government salary scale, estimated that he worked full time on the case for about a year before the February 2012 opening arguments, and part time for several years before that.
Once jury selection started in late September, prosecutors John Gallagher and Steve Mellin also worked exclusively on Savage, he said. And a paralegal joined the team.
Like Purpura, Mellin, a Washington-based prosecutor, relocated for the trial. He stayed at the Hotel Monaco, a $350-a-night boutique hotel near the federal courthouse.
An office spokeswoman declined to discuss that except to say: "When accommodations are necessary, they are made at government rates."
And still the case goes on. Kidada Savage and Merritt are awaiting sentencing and hearings on post-trial motions filed by their lawyers. Kaboni Savage's attorneys have also filed motions asking the judge to overturn the verdict or sentencing.
Any decision is likely to be appealed.
Savage will wait with 58 others on death row. Only three inmates have been executed - and none in a decade - since the federal death penalty was reinstated in 1988.
Troyer, 55, said he expects Savage will cost the government time and money for years to come.
"I wouldn't be surprised if this case outlives my longevity with the department - if not the earth," he said.
Contact John P. Martin at 610-313-8115, at email@example.com, or @JPMartinInky on Twitter.