At this point, manned space flight is largely a waste of resources. There is no point on landing men on the moon again, and there are no resources there with which to sustain a colony. A manned moon base would simply be a colossal drain and serve no real purpose.

There may or may not be more resources on Mars which might serve to partially sustain human habitation, but almost certainly most of what people will need to stay alive will need to be brought with them. Atmosphere, water, food production...pretty much everything will need to be brought from earth, at fantastic expense. And because Mars' gravity is stronger than the moon's getting people and things back will be problematic too.

Until there are major breakthroughs in propulsion that will allow much faster, cheaper space flight, and until such time as we can figure out how a Mars colony can be close to self-sustaining, manned spaceflight will remain expensive and largely pointless.