It will never happen, and not because of the money. The money is there, the "city" is just unfeasible from almost any angle. Setting aside how you're going to

It will never happen, and not because of the money. The money is there, the "city" is just unfeasible from almost any angle. Setting aside how you're going to build a "green" city in the desert, you can't just stuff an entire city into a line. This might work if it was a district (one of those live play work places) but as an entire city it just raises far too many questions. How would essential services operate? How is an ambulance supposed to work without roads? Biggest hurdle is that there seems to be zero room for expansion or adjustment. You build this line and what happens in 20 or 30 years when the "city" is bursting at the seams, you have X Y and Z problem and no way to fix it because you build your city in a straight line and not like a normal city with room for expansion. If this ever happens it won't be a "city" so much as it will be a tourist district. They have enough money to build this thing for sure, just not sure if they would want to go the "city" route since there are so many variables that will be out of their control and highly constrained by the design.