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.
You'd probably be better off reading the full article but some people want executive summaries.
Rick starts with certain assumptions and follows them to various conclusions about the interstellar economy.
Therefore if the cargo was available for free at the origin the minimum selling price at destination is 0,000 per ton, or 0 per kilogram.
The implication is that only very high value cargo can be profitably shipped interstellar.
This means the ship owner must earn 0,000 of profit per ton of cargo.
This ignores taxes, station docking fees, and fuel.
With creative maintenance, the service life might be longer than 30 years, see below.
Question: how many cargos can a merchant starship carry in 1 year?
Using a long series of estimations whose details can be found in Rick's article he concludes that the annual operating cost for an airliner is about million (not counting fuel, landing fees, and taxes).
An airliner's purchase price is 0 million so one year's uses costs about one-third of the purchase price.