and that unlike the real world you can actually wipe them off the face of the server if you need to.
A government could do that IRL if they wanted to. It just has to pass a law prohibiting said corporation from selling, shipping, mining, farming or manufacturing in their country. It doesn't wipe them off the face of our planet, but it wipes them off a country. And a server can be seen similar to a country.
A truly free market with no regulation whatsoever has a big weakness: Once a monopoly forms, which will happen eventually if it isn't regulated, all its benefits are null, as the monopoly can do however they please without any risk, as there is no competition, that customers could choose. the exception to that rule would be governmental monopolys in democracies, as they will still need to be voted in by the people, a group to which nearly all their customers belong.
However, a market in a game is never without regulation, as the game's mechanics will always regulate what can be traded in which ways.
When ever resource is distributed evenly, it is impossible to form a monopoly, as anyone at any location can become a competitor, that will be able to undercut the monopoly. Now the monopoly could offer their goods at a price lower, than they pay while acquiring their goods, but the moment they stop with that, they need to make up for lost money, and at that moment they will be undercut from randomly appearing competition. However, these very mechanics would discourage trading in general, so they aren't the best option, if trade between players is supposed to occur.
In addition, I don't think this:
And how does this relate to SM? Well, you get more money the better you build. You build better the more ships you can view. You can view more ships the more money you spend.
Use A to get B. Use B to get C. Use C to get even more A.
will occur with too much of an impact, as one does not necessarily need to have a ship to learn how to build it. Sufficient images of a ship can be enough, at least in starmade. And it is unlikely for someone, who managed to become a monopole, to actually forbid anyone to share images of their ships. And then there will always be those, that fund themselves with donations or some other means of getting assets, buying a ship, and just releasing how to build it for no or a very low cost. (This only applies in starmade, as the quality of a block placed on A at X by P is no better, than the quality of a block placed on A at X by Q, and since the means of production in starmade are low cost, so long as you don't speed it up too much)