That is, assuming a full cargo turnover at each port of call, how many one-way runs can the ship make? From departure planet orbit to FTL flight to arrival planet orbit. Assumption: each trip requires one month for servicing, maintenance, selling the cargo, buying new cargo for the next run.This makes each trip four months from departure to departure, or three cargos per year.They go fast, can carry lots of people and cargo, and are the most advanced technology that can be massed produced.The ticket prices will not be similar between airliners and starships because FTL interstellar travel will probably take more than a few hours for the trip.
That is, selling price at destination MINUS purchase price at origin must be 0,000 or more.
The leader of the thalassocrats is of course called the thalassiarch.
Men, my brothers, men the workers, ever reaping something new: That which they have done but earnest of the things that they shall do: For I dipt into the future, far as human eye could see, Saw the Vision of the world, and all the wonder that would be; Saw the heavens fill with commerce, argosies of magic sails, Pilots of the purple twilight dropping down with costly bales; This section is basically a rough outline of Rick Robinson's Interstellar Trade: A Primer.
You can alter some of the assumptions yourself to tweak the economy to suit your science fictional background.
Merchant Starship Costs Assumption: starships in the interstellar empire are equivalent to present-day jet airliners.