That has never been the idea or the way to colonize the Solar System. The permanent colonization of the Solar System can be accomplished only by self-sustaining economies. The costs are simply too astronomical for such an effort to be sustained by any form of deficit government spending imaganiable. The Earth’s gravitational well is simply too expensive in energy to permit very much transport out of the gravitational well. Human colonization of space will become sustainable only after the off-planet presence has become a net exporter of goods and services to the Earth and itself. Necessarily, this will begin with very small numbers of humans providing extremely high value products and services to the Earth. Later on humans will produce goods and services for the extraterrestrial industries and economy that will in turn expand the extraterrestrial human populations, infrastructures, economies, and habitats. After the extraterrestrial human population reaches the point where it outnumbers the human population of the Earth, you will find the extraterrestrial population’s ancestors come from only a very small number of original space emigrants who were the pioneers of the colonization of the Solar System. More than 99.9% of Earth’s present day population would never have any descendants among the extrateresrial populations.
It was once observed that if there ever were a hypothetical instantaneous trasporter to beam emigrants off of the Earth to extraterrestrial habitats because the Earth and its remaining inhabitants were doomed to destruction, it would be impossible to evacuate more than a fraction of the Earth’s population. The reason given was that humans would breed more humans faster than the transporters could instantaneously transport them off of the Earth. I don’t know wheether or not their math would hold up to scrutiny, but the general principle is certainly applicable in the case of colonizing the Solar System with currently envisioned technologies.
The most valuable material in space will not be what we send from here, other than our mechanical and organizational skills. It will be the material that is already there.
Have you not heard that for an item to be launched into space, it has to be very valuable, and very needed? What then of the stuff that is already there?
What is needed, in space, is the ability to use the energy that is there, on the material that is there, with the design purposes that we have here. That can mean sending humans, or letting them operate machines remotely to gather, process, and manufacture things that will be needed for other activities.
In building colonies in the New World, the Old World did not send pre-packaged colonies. They sent tools, and workers to employ them. The forests of the New World became the ships of the whole world.
The ships of the Solar System will be made off Earth. Eventually, system colonies will trade with each other more than they will with Earth, for what will Earth have that they would need?
It's not too difficult to find that out. The population of Earth grows pretty slow - so slow that we can treat it as a constant. (It does not change considerably within a year or two.)
There are 6 billion people on the planet. Let's say the average lifespan is 70 years (all countries combined.) Within 70 years 6 billion people will die, and another 6 billion people will be born to replace them. This means that every year (6,000,000,000/70) = 85.7 million people are born, or 235,000 per day. That's a serious number.
Now, let's assume we have a teleport that accepts a single file of people walking into it. People can walk at 2.5 mph, and you want them to be spaced by 2 yards. 2.5 miles of the line will contain 2,200 people, and they will go through the portal within 1 hour. Since the teleport will not be closing for lunch, 2,200 * 24 = 52,800. So now we know, we need about five teleports - or one large enough to admit five people abreast. This does not look like an impossible requirement, assuming that you have the technology for constructing a teleport across the galaxy :-)