The new Nikon Nikkor Z 120-300mm f/2.8 TC VR S lens with a built-in 1.4x teleconverter is rumored to be priced in the $8,000 range. This is not confirmed, and it is just the initial informtion I received. Nikon may adjust the price prior to announcement based on the latest geopolitical developments.
B&H Photo currently does not list a price on their product listing page.
The new 120-300mm lens is expected to be officially released by the end of 2026. Keep in mind that the release timeframe has not been finalized, and there may be delays.
The old Nikon Nikkor AF-S 120-300mm f/2.8E FL ED SR VR lens for F-mount (now discontinued) was priced at $9,499.95 when announced back in 2020. Nikon USA was recently selling that lens for $6,649.95, so $8-9k for the new Z-mount version is possible given the latest technologies and the advantages of the Z-mount: