As One World Trade Center has passed the 90th floor of its construction, it's reached another milestone: It's now costing more than $3.8 billion. The Wall Street Journal reports that it's the "world's most expensive new office tower, according to people familiar with the matter. The new figure [is] up $700 million from the latest public estimate."

The drama around the construction of the former Freedom Tower has played out over the previous years, most recently with the building scrapping its shimmering bottom (it was replaced with a less expensive option) and attracting big name tenants, with the help of real estate developer Durst. And the Port Authority has raised tolls, but claims none of the increase will go towards the building's construction.

According to the WSJ, "One World Trade Center's construction is vastly more expensive than a traditional office tower, in large part due to security costs associated with building the tallest building in North America on a site that has been the target of two separate terrorist attacks (the site was also bombed in 1993). Once known as the Freedom Tower, the 1,776-foot skyscraper sits atop a heavily reinforced, windowless podium. It also has a thick core of concrete and steel around its elevator shafts. By comparison, other-high profile buildings around the world have been far less expensive. The developer of the Burj Khalifa, the world's tallest tower, in Dubai, has put its cost at $1.5 billion."

The Regional Plan Association's Robert Yaro explains why the Port Authority isn't expecting to make a profit, "It was as much about making a political statement as it was an economic decision,. This is not a project that's standing on its own—it was never intended to be."