I think we are missing some important cultural points here.
Your average German hunter tends to be a bit more well to do than the average American hunter. It is certainly more difficult (and more expensive) to get a Jagdschein than your average American ticket. This carries with it some other follow on requirements.
With more disposable income, your average Jaeger is going to be more willing to invest in his equipment. Similarly, the companies making the arms will be working towards different price-points. And, of course, their target market is much smaller, so much more focused. And hand work is valued.
In the US, the average hunter wants reasonable accuracy, reasonable reliability, and more than reasonable price. Mass production is king. And you can find an incredibly accurate rife for a very low price. Pretty? Hand worked? No. Dead on balls accurate? In spades. Your American gun company needs to sell many more weapons to stay in business, and at a competitive price. Oh, and your average American hunter is probably not going to travel farther than he can drive, let alone to Africa.
When I was in Poland, my guide was very happy with his Ruger American in .308. It did not cost the bleeding eyes out of his head, and it was as reliable and accurate as some more expensive arms.
I find the car comparison also interesting. Having lived in Germany, I noticed things. For example, the starting price on a BMW is much lower there... but that BMW is NOT available in the US. US spec cars will have leather seats, larger engines, and all kinds of other "standard equipment" that is an extra cost option in Germany. The domestic target customer is much different than the export customer. Of course, when you're willing and able to spend more, you'll get much more. As far as Porsche/Aston Martin? One is a street legal race car, the other a GT. They are not at all the same thing. Every engineering choice is a compromise. The Porsche prioritized track performance. The Aston had some different things in mind.
The whole discussion is apples and oranges.