How did you come to the conclusion that the 8/16 version would be the equivalent of the 4 core 8 thread 7700k? You should be looking at the top end 4 core 8 threaded models. These won't match intel's top CPUs in most applications, but should be quite a bit cheaper (...
The equivalent would be the Ryzen 1800X (according to the chart) and would run me $642 (600 Euros)? I guess this is where the value is, though I wouldn't spend over $500 on a CPU. This keeps me with Intel if the leaked prices are correct. It's a far less risky ...