Ah, you specifically want the “premium” knob. I’ve seen a few on Rennlist and very rarely on eBay. Not going to find them for much less though unless you get lucky.
I have this one. For the $$$ it is very nice and even has an LED option if desired.
https://www.ebay.com/itm/ICT-shift-gear-knob-gaiter-boot-leather-Porsche-911-Typ-996-with-frame-C-62/252917760420?fits=Make%3APorsche&hash=item3ae312c1a4:g:NEYAAOSwX61ZCdwM