Have to say, I'm pretty surprised to see this pricing decision elicit so much drama here. I'm speaking only of the initial responses. Perhaps I'm wrong, but I just assumed this was an artist not as well known for darker ambient music having a little fun with some of the more cliched tropes of the genre. Even if I did have reason to suspect the price reflected a sincere religious conviction, the label "Satanist" is pretty damned uninformative. A self-identified Satanist is at least as likely to be a nature-loving peacenik or a theatrically inclined but otherwise harmless atheist as the depraved caricature the term traditionally connotes.
I agree, the term 'Satanist' is usually bandied around in an uninformed manner. Most so-called 'Satanists' are just playing at it. Pan / negative energy archetypes worship has been around for a long time before it was referred to as anything to do with the christian 'Devil'. I think there are individuals around whose actions are most suitable to be described as 'satanic' - psychopathic individuals in power, who create war and famine for their own goals.
Back on topic, I think Stuart's response may well have been a reaction to a critical initial response.