Yes. And if the frackers were required to incorporate the external costs, it would be more expensive still.
I take it you mean LPG liquefaction and liquid storage is cheaper/easier than LNG. CNG is certainly common and useful, just not very compact, even at 3,000 psi. LNG is arguably safer, however, as it's lighter than air, whereas a major LPG leak can leave a lot of gas at ground level. And LNG is cold enough to quench hot bullets if they penetrate the tank. LPG isn't particularly cold until you evaporate some of it.
So have two e-editions with two prices, one that comes out early with the hardbacks and includes something extra... an additional short story, visual media, lack of DRM, whatever, and one that comes out later with just the main text. Or... just drop the price of the ebook when the softback comes out.
Price elasticity of demand curves are just that—curves, so dropping the price below $9.99 doesn't mean revenue will continue to grow. However, I won't buy their claims until I see their curve, and I bet it supports that dropping the price to $8.99 or even $7.99 increases revenue even further.
How many think that paying ten dollars for something for which the marginal cost is nearly zero is rather absurd? Virtually free replication is something for which capitalism is not well suited, hence all the manufactured scarcity we see.
Only through hard work and perseverance can one truly suffer.