Making Starship propellant on-site instead of buying it merchant cuts the bill from about $2.19 million to roughly $210,000 a flight, but the binding constraint is physical: merchant supply needs about 389 cryogenic tanker deliveries per launch, a pattern no road fleet sustains past the low hundreds of flights a year. That is why the $100 billion Louisiana campus puts propellant production and power generation on the site plan.