Suborbital point-to-point transport using a StarShip does not require a booster. You only need a booster stage if you need to accelerate to orbital velocities.

Suborbital point-to-point transport using a StarShip does not require a booster. You only need a booster stage if you need to accelerate to orbital velocities. That brings the cost down dramatically. A major reason the StarShip is going to be more affordable per launch than a Falcon 9 is that the StarShip is (planned to be) 100% reusable. Falcon 9 (and Electron) always disposes of its 2nd stage. Hopefully other launch companies can provide 100% reusable alternatives to StarShip just in the name of diversity and planetary capacity. Musk points out that larger ships have an advantage here due to volume vs surface area and the fixed weight cost of avionics.