Starship in its current incomplete form (v3 fully expendable ship and booster) already has the lowest cost to orbit in $/kg of any launch vehicle ever. It's around $400/kg to orbit fully expendable.
Add in booster reuse, which SpaceX has already demonstrated on test flight 9, and the cost to orbit drops to $200/kg.
Add in booster reuse, which SpaceX has already demonstrated on test flight 9, and the cost to orbit drops to $200/kg.