[helsinkiandrew]

Actually rocket fuel although very old fashioned doesn't seem that costly.

Falcon 9 flight to LEO costs $200K in fuel but can lift 22,800Kg. If a person and their seat could be squeezed into 200Kg that's only $2K per person. I think the biggest cost is that the forces and extremes of temperature mean the 'rocket' needs to be engineered and maintained very well as any small failure is likely to be catastrophic - its very hard to abandon ship or divert to the the nearest airport.