"The closing quote from the article is interesting and I have no idea what to make of it. Apparently Arthur C. Clarke calculated that it only takes 1000 KwH of energy to lift an average sized man out of the Earth's gravitational field. That's not very much, so I'm not sure what's missing from that calculation. According to the article that's $20 in electricity costs in 1970 compared to $20 billion required for the Apollo program. Does anyone know how that 1000 KwH number was arrived at? It obviously takes many magnitudes more energy to launch a rocket to carry a human into orbit."

That is _IF_ the only thing being lifted out is an average man, but when you add in the rocket motors, fuel tanks, fuel, etc..., the costs to lift all of that start to soar.
Then you are adding in the cost to manufactur all those parts, and their support structures.