Thanks for your comment. The price of that motherboard has been adjusted.You may be right that prices in Europe tend to be higher than e.g. in the US. But it's not as bad as your listings suggest
Supermicro X10DRi retail ab € 399,11 (2020) | Preisvergleich geizhals.eu EU
That's just one of the items, some of the others have similar problems.
I am not here to trash talk your offers, but with the prices you listed, you will have a hard time selling any of the stuff here.