This is a nice illustration of why, even though low Earth orbit is only 1/1000 the distance to the Moon, in terms of energy expenditure it's already more than halfway there. It's a shame we've spent decades going that far but no further. 
Here are the numbers behind that. This is via Brad Blair et al. researchgate.net/publication/26…
Er, actually, for energy expenditure you use delta-V squared, which makes low Earth orbit much more than halfway to the Moon.
