[John Jamieson]

It's not the cost of the energy, it the cost of turning the energy into altitude and velocity that hurts. The Space Shuttle's actual fuel cost is well below 1% of the total launch cost.

[NonZeroSum]

But the point of the space elevator is that it reduces the cost of transportation to a little above the basic energy costs, so I don't understand your original comment.

[John Locke]

You're right. The energy required to accelerate one kg to escape velocity is approximately 18 kilowatt-hours. For that much electricity, you'd typically pay about two dollars (well, maybe 20 in California).

Chemical rockets are very, very inefficient.