In my opinion it is very clear that the phormula of DD (peak - throug)/peak has to be used with quotes no %, and not calculating differences of %
It is the way that makes sense transforming to euros as you did with the example.
Completing your example, if you invest 8.000 at quote 250, and you lose 2000, the quote will be 187,5 --> DD=25% in both cases
The % in the chart would be 150% on the peak, and 87,5% after. The DD would not be 150-87,5=62,5%, and either 41,7%: (150-87,5)/150, it is 25% (250-187,5)/250 or (8.000-6.000)/8.000