They pay dearly for this though -- 7.5% of the price of the house goes to the notary/state. In the US it can be as high, but it's usually not, since most fees are fixed amounts.
It depends if the house is new or old. For a new house this ~2%.
There is a legal possibility to negotiate part of the notary cost (to lower it below the legal maximum) but the chances are thin (they get better for expensive houses).
