Musk said 5% of SpaceX is working on the project and that number will increase over time. That's already 250 of the smartest engineers in the world working full-time on the Mars project. They've already test fired the Raptor engine for the rocket and produced a full scale tank of the fuselage for testing. These guys aren't going for 'exploration' like Zubrin wants, they're going for full scale colonization.

Every ship produced is a new member of the fleet that continually moves between both planets. Opening up an interplanetary transportation corridor. If you're someone with the spirit of a colonist, an explorer, an adventure seeker (there are many in the world with that attitude) then Mars is going to be the place you want to prove yourself on. It is romantic, risky, badass, and there are no shortage of people who are going to take the challenge.

An ever increasing number of ships leave every 2 years, and you always have the option to come back. I can easily see people doing fundraisers to go, universities offering scholarships, governments setting up stations to claim some land, companies sponsoring infrastructure projects to say they have a presence on Mars, etc..