The three projects mentioned are three different concepts. TSI's South Sea project is to work with an existing country to build designer barges that have a look and feel of a floating island. Pretty expensive but the silicon valley folks are used to big projects and lots of money. Their project is geared more toward the wealthy.
If I understand Frusha, his project is more in line with a floating oil derrick. It is already tried and proven technology. It will be more expensive than just living on a boat but since JL is on here he can say better who he had in mind as users of his project, how many, and such.
I can speak for the Marinea Project. Its design is to start small and grow using existing technology. Designed after an early western town, the Village will start with a general store, hotel, restaurant, post office, saloon, instead of a livery stable we will have a fueling and fresh water station. We have all of that on an ocean going barge. We have one in mind that is already set up. Citizens of this here village will live in their own homes as they should. The early residents will be using live-aboard-boats. After we see how things work out, we will be selling floating homes that can handle ocean environments.
Phase two will be to build a town square and connected residential areas with the ability to grow. Marinea has four main criteria that it needs to follow. The project must be expandable, it needs to the right size no matter what the population grows to. Secondly it must be self sustaining, meaning it must produce as much or more than it uses. Third it must be replicate-able. As a pilot project it wouldn't do anyone any good if we made something wonderful that could not be replicated. And forth, it has to be sustainable, we need to start living in harmony with nature.
Marinea is membership driven. The members intend to build a floating independent country with a Libertarian government. There is very little structure as the concept is to plant the seed and see what develops by natural growth. This type of development is for everyone, even those of limited means. People will be adding 40% more people to this planet in the next 30+ years. Someone has to learn how to make ocean colonization a reality, and if we are first then we will make $$$ and a way for all those that come after us. The early bird catches the worm.
In the words of Hans Solo, "Look, I ain't in this for your revolution, and I'm not in it for you, princess. I expect to be well paid. I'm in it for the money."