Many buyers focus only on the asking price of a flat or house. In Germany, however, a long list of extra costs sits on top of the purchase price. If you do not plan for them, your budget can quickly become too tight. Here are the main hidden costs you should know about. 1. Property transfer tax (Grunderwerbsteuer) Every buyer pays a tax when purchasing property. The rate depends on the federal state and is usually somewhere between about 3.5% and 6.5%  of the purchase price.