What if that price you see in the book the ship is the STICKER price, in the shipyards of your Interstellar State the price of production is only 20% of the sticker price. Business do not go into 50 year speculation, but governments are always assumed as a "going concern" so they are the only ones who can get into this, 50 year financing (like in subsidized home ownership loans here in the Phiippines).
This brings me to the next What if - What if all ships smaller than a Freighter are considered "Subsidized" Trade ships. As Subsidized ships they have a bunch of duties an
- Half of Profits After all Expenses. Basically the ship Volitional AI will do all the accounting and back-office support for the ship owners. Even go as far as providing Market Analysis and a strategy, of course they are the ones who handle the back office work so they get to see all the revenues and expenses. They have a duty to make sure that the Interstellar State gets their cut. Note that the leverage of the State is that they have the power to stretch out the interest, at the same time negotiate with Shipyards/Suppliers for the maximum economies of scale.
- Employ Imperial Citizens as crew and provide them Training and basic living expenses, even allowing people to work for in return for training and basic living stipend. The Training can be achieved via UT's AI tutors in . The Ship can afford to a Microframe that has a specialized training VAI for the crew that is UT56-57 The AI may cost up to $20,000 using the AI creation rules in UT, capable of possessing and running all the Techbots, Androids, Robots, and Bioroids of the ship.
- Dictate where certain ships have to Operate. In dangerous, undeveloped, and frontier areas that need much needed trade infra, the State can use their influence over the duties of these ship owners to trade in places many are adverse to work in.
- Emergency Ships. In emergencies, they have to answer the call to provide aid, fight, support the fighting, etc... in a way this is one of the most effective ways to cheapen the cost of military and support operations over time. Shipyards busily churning out subsidized ships
If the State has property rights and self determination a strong element in its constitution then it is possible for these ship owners to own a ship, possibly inheriting a ship if it takes more than one lifetime to work towards owning one.
It is possible that subsidized merchants make up 99% of all ships in a Sci-fi setting. One of the main reasons is through the muddy way value is generated in an economy, the State's job could be to provide jobs and livelihoods and it does that by making ships and trade as cheap as possible.
What i find interesting is that this is a theoretical point where the State is merely there to be an entity that would make it possible for business to attempt risks they would never had tied, simply to keep confidence and value up.