The story of the smuggler, in the video player above, is part of the new CBSN Originals documentary, "Border Business: Inside Immigration." Watch the full documentary at the bottom of this page.

"I am a person that is bringing in illegal people," Alfredo said, his voice muffled by the scarf he's wrapped over his face to hide his identity. "According to America, I am a dangerous person because I am committing a crime, but, well, it's also a job."

Alfredo — not his real name — is a so-called coyote, a human smuggler. He works along the section of Mexico's border with Arizona centered in Nogales, a town that has a counterpart of the same name in both countries. It's a corridor controlled by the Sinaloa cartel, which was formerly headed by Joaquin "El Chapo" Guzman, the kingpin who was convicted in U.S. court in February on drug trafficking, money laundering and weapons charges.

On average, contracting with a smuggler costs an estimated $4,000 to $5,000; Alfredo quotes a somewhat higher figure, $5,000 to $6,000. He relies on a network of safe houses to keep his clients from being caught by local law enforcement before they cross. Approaching the border with a machete in hand for clearing brush in the harsh desert terrain, Alfredo said he relies on spotters hidden throughout the landscape to watch for border patrol agents and other authorities.

Smugglers like "Alfredo" charge thousands of dollars to get migrants across the U.S.-Mexico border. CBS News

"The people watching, they'll let me know. They'll call me and they'll let me know," he said.

Alfredo said he's been smuggling undocumented migrants across this section of border for at least seven years. According to the Department of Homeland Security, between 80 and 95 percent of border crossers who were apprehended in 2015 had hired a smuggler, a big increase since 2001.

The number of migrants apprehended at the Southwest border in February 2019 more than doubled compared to the same period last year. President Trump has declared a national emergency over illegal immigration, calling for $8.6 billion in funding to build hundreds more miles of border wall. He's even threatened to shut down the border entirely.

If the wall were fully constructed, Alfredo says his services would be in even greater demand and that smugglers could jack up their prices by thousands. "It won't be as easy to do things the same way, so the situation is going to get more complicated for all the people that want to get to the United States," he said.

Some fear the price hike could lead migrants to commit additional crimes in order to pay their way across. According to the Drug Enforcement Agency, U.S. agents are already seeing a slight uptick in migrants being utilized as drug mules.

"There will always be a way for people to cross over there. One way or another the people that work in this will find a way to work, to make their livelihood," Alfredo said.