https://www.techpowerup.com/292907/silverstone-intros-gm-series-redundant-power-supplies
 
SilverStone introduced the GM series of redundant PSUs in the PS/2 mini-redundant form-factor. These are functionally similar to the Twins PRO series from FSP. Much like the Twins PRO, the SilverStone GM-series features two detachable and hot-swappable sub-units. The series includes two models based on capacity, the GM 600 Silver, and the GM 800 Silver, with capacities of 600 W and 800 W, respectively.

Both models offer Cybenetics Silver-rated efficiency. Each sub-unit features a single +12 V rail design, and relies on a pair of 40 mm server-grade fans to keep cool. Each of these fans has a maximum noise output of 51 dBA. You get most common electrical protections, against over/under-voltage, overload, overheat, and short-circuit. The main body, which docks the sub-units, puts out fixed cabling. The GM 600 Silver is expected to be priced at USD $599.99, and the GM 800 Silver at $699.99, when the two start shipping late-March in Asia, and April for the rest of the world.
 
I think the prices are reasonable for this type of redundant power supply.