At Computex 2019 Intel previewed the third and perhaps final variant of their flagship Core i9-9900K, and with all-core Turbo Boost modes breaching the 5GHz barrier (where previously only one core would reach that milestone), the Core i9-9900KS is an end of stream Special Edition/refresh akin to the Devil's Canyon CPUs of the Haswell era, tailored to be the best possible variant of Coffee Lake that can be reasonably sold through regular consumer channels.
Price wasn't mentioned during its public unveiling this past May, just raw specifications for the CPU lead by that 5GHz all-core Turbo. Its base clock of 4GHz is already 400MHz greater than the i9-9900K, plus its all-core Turbo is 300MHz higher; the chip will almost certainly be a stock CPU performance record breaker if nothing else. More recently the CPU TDP was pegged at 127W, considerably higher than the 95W of the 9900K and 9900KF and likely necessitating pretty robust cooling to hit its potential. While Intel may have worked wonders in pushing the architecture and silicon to its limit, they haven't been able to break the laws of physics just yet.
Pricing wasnm't available at the unveiling but appears to be starting to leak out from retailers jumping the gun. Late last week MWave in Australia accidentially listed the i9-9900KS at an eye-watering AUD 899, just a touch over US$600/£489 excl V.A.T. and a significant mark-up over the 9900K's $488 launch MSRP. Other netizens known for leaks have also raised a similar figure. Both sources have subsequently been shut down, presumably after pressure from Intel, and as always pre-release pricing should be seen as subject to change.
Although pricey, it will likely be released against the backdrop of an inflated price for AMD 3rd Gen Ryzen CPUs caused by extreme scarcity. Pre-order pricing of the Ryzen 9 3900X (in advance of additional stock) is now up to £559, so ~£585 for Intel's Special Edition doesn't sound quite so bad; and that doesn't even cover the shenanigans surrounding AMD's Ryzen 9 3950X.
Intel's Core i9-9900KS is expected to hit shelves next month.