Is the Porsche 997 GT3 RS 4.0 a good investment?

The thesis

The 997.2 GT3 RS 4.0 is the final iteration of the 997 GT3 lineage and the last manual GT3 ever built by Porsche—a 4.0L flat-six producing 500hp from the largest engine ever fitted to a street 911 at the time. With only 600 units worldwide and approximately 30 UK RHD examples, it combines extreme rarity with end-of-an-era significance. Values have appreciated strongly from the £128k original price to current UK levels of £380–550k, though the cycle is mature—recent sales show £495k as the benchmark, indicating the car has already experienced substantial appreciation and may be approaching a plateau.