People could one day sell homes on Earth, move to Mars: Musk

SpaceX Founder Elon Musk has tweeted, "I'm confident moving to Mars...will one day cost less than $500k and maybe even below $100k." Musk added it will cost "low enough that most people in advanced economies could sell their home on Earth and move to Mars." Responding to the user inquiring about the estimated costs, Musk said, "Return ticket is free."