Is the Porsche 911 a good investment?

The thesis

The 997.2 GT3 marries a 3.8L Mezger flat-six (435 hp, 9000 rpm) to a six-speed manual in what many consider the sweet-spot 911 GT car. It arrived with significant updates over the 997.1, and though not the final manual GT3 RS, it's the last pure, naturally aspirated, non-RS manual GT3 before turbocharging arrived in the 991 generation. Production was modest and European examples are available in the user's budget range; current average transaction prices sit around £105,000–£130,000 for clean examples.