German specifications is not enough. It needs to be made in Germany, using German (or other European) materials in order for it to be good. Hohners made in China are made with rubbish Chinese steel, and as a result for instance springs tend to break much much sooner than they ever would when German springs were used...
The Hohners that are particularly good are the Verdi II (37/96) or Verdi III (41/120) and you can maybe even find a Verdi II (with white registers) from the German era, after service by a store, for around 600 euro.
You cannot really trust any vendor who sells Chinese rubbish and calls himself an accordion specialist. As long as you cannot get a Chinese accordion for say 600 euro new that is at least as good as a serviced old German or Italian accordion of similar spec, buy European and run away from the Chinese accordions! (I am not generally biased against the Chinese, but when it comes to accordions they still have decades of learning to go before they are likely to produce something good.)