That's around 10kg of propellant per 1kg of first stage.Originally posted by enigma
Actually, propellants are such a small percentage of the cost, that they can be more or less neglected.
The cost per kilo of LH2 or LOX runs on the order of $1/kg when purchased in bulk quantities.
So, for the first stage of a [...] which has a mass of 26,760kg you can make the approximation that it cost around $1.9 Billion to develop and $144 Million to make the first one. Compare that with around $200,000 for the propellants.
Materials? Let's assume $10/kg and, being generous, another $10/kg for assembly.
Electronics? Likely but a fraction of the cost of the propellants; $100k tops.
That leaves the complex machinery (rocket engine, pumps), assembly, and overheads; overheads should be able to be brought down to ~<20%.
This toy calculation suggests that enigma is right to focus on getting to 'mass production'; a not unrealistic target per-launch cost of getting to LEO is $100 to $1,000/kg.