It’s a big lineup. As for the K65 PLUS, considering the cost of building a custom keyboard, and Corsair’s choice to include audiophile-grade features like pre-lubricated switches, sound isolation, and PBT keycaps, I think $159.99 is not bad. all. The only weak point for me is that the key labels are not illuminated, but this is consistent with the area of the keycaps used.
All in all, the K65 PLUS is a very impressive product, with a (subjectively) amazing typing feel and the quietest operation I’ve ever (not) heard from a mechanical keyboard. The K65 name might cause some confusion because it’s not a 65% layout, but regardless, only one keyboard in the K65 series is actually a 65% (they were 60%, 65%, and now 75%). What’s important is the quality, and from a hardware and usability standpoint, it’s really, really good.