Doing any business at all in Germany carries extreme business risk, by American standards. The attitude of Germans seems to be to just live with it and maybe get insurance. If you just have to accept courts will void 1% of your transactions (costing another 2% in legal fees) then you just make everything 5% more expensive to cover it.

This is why there's not much big tech in Germany. A single legal dispute can theoretically bankrupt any company, completely at random, at no fault of the company, but practically doesn't. It may be a low enough chance to justify investing thousands but nobody would invest a hundred million dollars in that.

> If I understand you correctly selling anything more expensive than cheap food to a child carries a high degree of risk in Germany.

Basically yes - the limit is generally considered to be the amount of monthly pocket money children typically get, so around 20 EUR for a 10 year old. And it would be possible for the seller to ask for a signed note of consent from the parent.

And of course the risk is limited to possibly having to revert the sale, which would be fairly rare for things that are just somewhat over that limit. Educated guess about how high the risk is for any given case are probably not hard.