Why would we make human civilization multiplanetary if there is no economic incentive to do so. Saying we could have 80000 people there is nice, but we would need some type of resource that would push us to do so. Take a look at Antarctica. Nice big space but we don't put people there because we don't have economic reason to do so!
We should stick to colonizing the moon first, as it actually has some resources like Helium-3 that we might actually use and thus support some colonies.
Aside from helium-3, there is no other reason to go to the moon. A quote from the Manifold series might be of importance here:
If you found the richest Lunar ore on Earth you would throw it out as slag.
There's no carbon or nitrogen on the surface, it would all have to be carted to the base there. That wouldn't give you something self-sustaining in an emergency as opposed to a colony on Mars.
And even if there's helium-3 there, so what? Current experimental reactors (including the upcoming Lockheed Martin reactor) tend not to need helium-3.