SAN YSIDRO, CA—The weekend kidnapping of 5-year-old Brendan Adler stalled Tuesday when the two men responsible for his abduction announced that they have no way to gauge the current market value of the boy.

Adler last month.

"We've run through a lot of figures, but the truth is we have no idea," said Troy Alan Curtis, the crime's primary planner. "We've been talking about anything from $1,000,000 to $10,000. It's all over the map."

The inability of Curtis and partner Steve Rodriguez to arrive at a realistic ransom figure has stymied the otherwise smooth kidnapping, which began Saturday morning when the pair snatched Adler from a local park and drove him to their abandoned-warehouse hideout. Yet four days later, the kidnappers say they are no closer to an accurate estimate of how much a boy in Adler's age and condition can fetch in the often confusing, constantly changing abductee marketplace.

Curtis also worried that the lost time has cost the kidnappers critical leverage in demanding a ransom "worth the effort."

"The price window is closing," Curtis said. "Steve thinks it could be good to keep the family waiting, but for all we know, they might think the kid is dead already."

He added: "It's the not knowing that's hardest for us."

"We probably should've given them a ballpark figure and just bargained from there," Curtis said. "Look at where we are now."

Shortly after bringing Adler to their safehouse, the two realized that though they had elaborate plans for collecting the ransom—including a fake public mailbox and two decoy briefcases—they had not determined a specific price.

In "a moment of panic," they briefly considered sending the family a "Reply-To" note, asking them how much they would be willing to pay. But the two ultimately decided that, no matter how carefully they phrased the question, the risk that the family would lowball them was too great.

Both men admitted that they never discussed a value before the kidnapping, assuming that the price was "a foregone conclusion."

"When it came to the amount of money we wanted, I guess we both thought, 'a lot,'" said Rodriguez, whose deep telephone voice made him the natural choice to be the liaison with the family. "Not knowing anything about him, I would say the kid is worth 50 or 60 grand. After casing his family's swanky home, though, that almost feels like it'd be a steal for them. I'd hate to find out later in the papers that they would've paid up to half a million."

"On the other hand, we wind up looking like we didn't do our homework if we go high and it turns out the family doesn't have that kind of money," Rodriguez said. "It's a real balancing act."

The two first-time kidnappers said they were "frustrated with the whole process," and would possibly have been able to come up with a more straightforward amount if they had abducted the Adler family's 3-year-old daughter, Amity.

Rodriguez and Curtis outside their hideout just after a trip to the store to buy Gummi Bears for Adler.

Said Rodriguez: "You wonder, is a girl worth more than a boy? Is younger better? But it's pointless to second-guess the decision we made."

"If we had thought to scuff him up a bit and send pictures, I bet we would have been able to name our price," Curtis said. "But some say roughing them up lowers the value. See, I just don't know."

At one point, according to the kidnappers, they removed the boy's gag and blindfold to ask him what he thought his parents would pay to get him back alive.

"That was no help at all," Curtis said. "He cried for a long time, and it took a while just to get him to speak coherently." After giving Adler some crackers and letting him watch TV, they posed the question again, and the boy estimated his own worth at "$100 million bazillion."

Curtis blamed the lack of any reliable source to consult for their failure to make an informed estimate. "There's no kidnappers' price guide, the Internet is filled with bad information, and Blockbuster is missing their copy of the Mel Gibson movie Ransom," Curtis said. "We feel a little bit like we're on our own here."

After spending more than $700 on gas, food, rope, folding chairs, and other supplies, the duo decided to factor those costs into a final figure and "work from there."

"Things like juice boxes add up pretty quickly," Curtis said. "Then there's the possible long-term upkeep to consider, which is a scenario we do not want to get into. In short, we're stuck."

Despite the complications, Curtis and Rodriguez are still hoping to come up with a workable number before too long and hope they do not have to resort to slaying the child.

"At this point, we're just looking to recoup our losses and get compensated for our time and energy," Rodriguez said. "We've put a lot into this. Killing the kid would feel like throwing that all away."