A Texas Monthly article says people are regularly using homemade ladders built from $5 worth of materials to climb Trump's border wall in Texas, which cost $27 million a mile to build:
Despite its obvious vulnerabilities, some border agents maintain that the wall serves a useful purpose. While it won't stop everyone, it will slow them down and give agents time to react, said Chris Cabrera, a McAllen-based Border Patrol agent and local spokesperson for the National Border Patrol Council, a labor union that supported Trump. "Nine times out of ten we're going to catch them," Cabrera said of immigrants who use ladders. But lately, Border Patrol agents have been swamped with the volume of immigrants in the Hidalgo area and cannot effectively respond to climbers. "We have people turning themselves over, and at the same time, when it's dark we have people with ladders, but we got nobody to go over because we're tied up."
I'm not sure who built the wall described in the above article, but a good portion Trump's wall was built by Fisher Industries, run by ardent Trump supporters. The Wikipedia article about Fisher makes it clear why it was the idea builder for Trump:
President Donald Trump has lobbied for the company to receive contracts on the US-Mexico Trump wall, to the Department of Homeland Security, to Todd T. Semonite of the Army Corps of Engineers, and promoted the company in an interview on Fox News with Sean Hannity. Jared Kushner has also endorsed the company, as well as freshman North Dakota senator Kevin Cramer, to whose campaign the Fisher family contributed $10,000.
Tommy Fisher has appeared on local and conservative TV and radio and is a donor to several charities and the Republican Party. Senator Kramer suggested Fisher's Fox News appearances are what attracted Trump to the company.
The High Plains Reader has documented environmental violations and tax evasion by the company, including 169 citations and paying $1 million in air quality violation fines in Maricopa County, Arizona over the past 10 years. In 2009 Michael Fisher, then-owner of Fisher, pled guilty to nine counts of felony tax fraud, being sentenced to 37 months in prison and over $300,000 in restitution. The comptroller also pled guilty to one count of conspiracy to defraud the United States in 2009. Another former head of the company, David William Fisher, pled guilty in 2005 to child pornography and was sentenced to 10 years in prison. He was released on April 30, 2010.