These people will put down $1 million dollar deposit to make it seem like they are serious about completing a deal, and will just let the timeline expire forfeiting the entire deposit!
Forget about the negative interest rates. Unless you can tap into the high yield corporate debt market, then dealing with these rich people is hopeless.
Source: Been around a lot of wealthy Europeans that talked a big game. It is the most ridiculous stable business climate on Earth. I do not recommend, especially for tech.