Comment Re:Erm... (Score 1) 120
It will never cost that little. A Falcon 9 has about 400 tons of propellant. If it were all commercial diesel, it would cost $400,000, or $17 per kg of weight launched to LEO. But of course it's not commercial diesel. Liquid oxygen and RP1 are both much more expensive.
Starship burns methane, not RP1.
Between SuperHeavy and Starship, a fully-loaded stack needs 3500 tons of LOX and 1000 tons of CH4. So what do those cost?
Well, oxygen is easy to get from the atmosphere, so the cost of LOX is really just some equipment (which isn't terribly expensive to buy and maintain) plus electricity, and the cost ends up being dominated by the cost of electricity. It takes between 150 kWh and 800 kWh to separate and liquify a ton of oxygen, so if you're paying $0.10 per kWh, LOX costs $15-80 per ton. There are some other costs to handle and store it, so let's say $100/ton.
CH4 can be created many ways. The cheapest is probably to purify natural gas, which costs about $190 per ton (that site shows ~$5 per 1000 ft^3, and a ton is 38k ft^3). Add some costs for purification and cooling, so call it $250/ton.
3500 tons LOX * $100/ton + 1000 tons CH4 * 250/ton = $600k. Musk usually calls it $1M, which seems pretty reasonable, since they're probably not separating/purifiying it themselves and there transportation costs. 150 tons of payload to LEO with $1M worth of fuel means the fuel-only cost is $6.67/kg.