I have not checked up recently on the world’s skyscraper constructions .. so here is an update! (In another life in another universe I would have been an architect, I believe). The Kingdom Tower is under construction in Jedda, Saudi Arabia. It will be the first tower to reach all the way up to 1,000 m with an inhabitable floor count of 167 (2 below ground), and a total height of 252 floors if the uninhabitable ones in the spire of the tower is counted as well. It is estimated cost is US$ 1.23 billion, and it was designed by American architect Adrian Smith, who also designed Burj Khalifa.
Check out http://www.skyscrapercenter.com/ and Tallest 20 in 2020 for beautiful line drawings of the world’s skyscrapers.