Is the Porsche 911 GT3 RS 4.0 a good investment?

The thesis

The last Mezger-engined GT3 RS and final 911 with both manual and naturally-aspirated 4.0L flat-six producing 500 hp. Only 600 built globally, making it far scarcer than later GT3 variants. Already appreciated substantially—median now £437,200, with recent record sales above £800k—but Hagerty and enthusiasts view it as the high watermark. Risk is that it has already run hard.