A summary of this article:
Last year, Musk unveiled his plans to colonize the Red Planet and make it fit for human habitation.
As Musk notes, "You cannot create a self-sustaining civilization if the ticket price is $10 billion per person." In order for it to be viable, Musk asserts that the cost should be about $200,000-equivalent to the median price of a house in the United States.
"Mars V2 plan coming soon, which I think addresses the most fundamental flaw in V1: how to pay for development & operation of giant rockets."
According to Musk, the version one has one fundamental flaw, which is the cost of developing and operating giant rockets.
According to V1 of the plan, getting to Mars depends on a reusable rocket-and-spaceship tandem, which Musk has called the Interplanetary Transport System.
Reducing the costs to developing the ITS is crucial, especially since Musk himself has already put a cap on how much a trip to Mars should be.