I think the price of the SxxA850x and S27B970D is partly because it's new and Samsung are attempting to get the best return on their 'new' tech (not genuinely new as it's an IPS copy) so the marketing is about pitching it as a top of the range product, and in the case of S27B970 they are pitching it as a top of the range 'designer' product next to the Apple 27" display. It's not so much what it is worth by any rational measure, as what they think the market is is willing to pay.
As it appears to be not quite as good as IPS, it's tough sell. I imagine the Samsung prices will continue downward. It's not cheap enough to take many sales from Dell & HP, Samsung don't really compete with NEC/Spectaview or EIZO/Colouredge, and those who covet the Apple product are still more likely to buy that while the prices are close.
Makes sense.