Following up on fastfreight's post, Shunyata is one of the few power conditioner manufacturers that have patents which publicly disclose aspects of their technology. In particular, their two primary power conditioning technologies implemented in the Everest (and also the 6 outlet Denali, but not the two outlet version) are referred to as QR/BB and NIC (noise isolation chamber).
If you want to read about them and debate their technical validity, see below (just delete spaces):
QR/BB - https :// patents .google.com/patent/US10031536B2
NIC - https ://patents .google.com/patent/US8658892B2
Re: the number of units for sale, there are a number of possible explanations. Quite a few times I have seen this happen when a new and improved product is coming out at some point and those "in the know" are looking to dump their units early (most recently to my recollection, this happened with MSB Select DACs right before the public announcement for the Cadence) so - an Everest v2 is on the horizon? It also could be, as others have noted above, power conditioning tends to be very system dependent / controversial.
All I will say about the Everest in particular is that it has some credibility in the industry, and in my experience, absolutely smokes the Audioquest 7000, which is commonly listed as its primary competition in terms of price / target application.