[weby]

The $4000/ton price of Jet fuel on spaceships p46 seems way too high.

Of course such values will depend on how plentiful such is in the setting but it is off by a factor of >10 compared to 2016 refinery prices. The monthly average refinery price of jet fuel/ton has varied from 350 to 450 usd. That corresponds to about 280 to 360 Gurps dollars. As comparison the prices for liquid hydrogen and rocket fuel seem about right for current prices.

So in a fairly plentiful oil scenario like current earth 1/10 of the price or $400 would seem fairly good approximation.

As a side note: The $400/ton would make the Molniya-class ramjet from spaceships 8 more reasonable. At $4000/ton the fuel cost would be almost $12000 each and yet the Transhuman space base book says that such transit costs $2000, so the $1200/passenger fuel cost would make it closer to that $2000 in total expected operating costs.