This is the 17th anniversary of 9/11. During the years that have passed large numbers of experts have established conclusively that the official government account of the event is false. Every year fewer people believe the unbelievable conspiracy theory that a handful of Saudi Arabians outwitted the entirety of the US National Security State and attacked with hijacked airliners the World Trade Center and the Pentagon. Nevertheless, the official story still stands, just as the official story of President Kennedy's assassination still stands despite majority disbelief, just like the official story of Israel's attack on the USS Liberty still stands despite all evidence to the contrary. In the US the government never corrects its proven lies.
People all over the world are amazed that Americans could witness videos of the two towers blowing up floor by floor and the obvious controlled demolition of Building 7 and conclude that they were witnessing buildings collapsing from asymetrical structural damage and limited, short-lived office fires.
The 9/11 fabrication and the Osama bin Laden myth were used by the Cheney/Bush regime to destroy the civil liberty protections in the US Constitution and to elevate the executive branch above both domestic and international law. This has culminated in yesterday's declaration of US lawlessness by President Trump's National Security Advisor, John Bolton, who stated that the US government will use any and all means to protect US and Israeli war criminals from prosecution by the International Criminal Court. https://www.cnn.com/2018/09/
The cost of 9/11 far exceeds the WTC buildings and the lives that were lost.
The real cost is the US Constitution, the separation of powers, civil liberty, and the rule of law.