I have the Apache with the latest revision C and even in high gain it needs to be in the 1 to 3 pm level to effectively drive balance HE6s using a Zeus cable. But even at 3 pm I haven't heard any distortion. But the Apache is $3000 compared to $3500 for the Dark Star but you do get a first class preamp as well.
While I can't say I know all the costs, I recall at one of the meets Ray commenting the parts cost including the case, custom transformer and DACT, the parts cost were over $2,000 before any labor. If the labor is 32 hours let's say at $50 an hour (which would be cheap with taxes and other costs), that suggest a $3600 price minimum before overhead. I don't think Ray is getting rich on selling Dark Stars. As some have said, it is more of a statement product.