I cover that in my second story Matthew: https://erik-engheim.medium.com/could-neutron-outcompete-starship-7776ee7af22

What people forget when comparing costs is that operational costs tend to be quite high. Often higher than the cost of building the rocket.

The Electron rocket is being designed to have very low operational costs. This may end up saving more money than producing the second stage.

Remember this will be a very cheap second stage, perhaps around $1 million or less to make. Operational costs are at least $4 million.

Of course Starship with is massive payload capacity will get very low cost per kg. But it may not be able to outcompete Neutron on cost per launch. This matters if a launch is not able to utilize the large payload capacity fully.