Colonists will have to earn a living

It seems I can no longer post at the space review {connection times out} so I will make my comment in this post.

So many good points brought up here, but I'd like to address only one...

Real colonists will have to earn a living somehow.

I can't see how you could disagree with this point, so let's consider it. Let me ask [what appears to be] a stupid question. How do people earn a living anywhere?

They provide products and/or services to others. Also important is each person serves a different market, some quite humble. So we don't have to imagine some silver bullet. Some will get along just fine providing their own special product/services to other colonists. Colonist will need things and will not do everything for themselves. They will specialize in what they do. Some of these might be big things like construction. Others may provide consumption goods like life support (food, water, oxygen, power, liquid methane, etc.) Food in particular will have no end of trade possibilities.

Where does the money come from to pay for these products and services?

A subset of the colonists will get their income from earth. What services?

Just go down the list of things people sell on earth that doesn't involve transportation of mass. Entertainment comes to mind. About one fifth of TV is reality show entertainment. This is paid for by commercial advertising which is completely independent of where production occurs. These reality 'stars' earn quite a bit more than the average salary which would be quite sufficient engine to power the entire local mars economy. This isn't even close to the only possibility.

People get substantial money for research. Do you suppose some martians would be in a unique position to be paid researchers? The research itself may be carried out on earth, such as we do now with rovers, but humans already on mars provide more capability at less cost for any new research that comes along.

I could do this all day long, but will not belabor the point. Martians don't have to invent some new way of making money. The existing ways will continue to work fine.