When do you need a patent attorney ... ?

The application for a patent, a trademark or other intellectual propriety rights at the German Patent- and Trademark Office (DPMA), the European Patent Office (EPA) or the European Union Intellectual Property Office (EUIPO) can in principal be made by the applicant himself.
Exception: applicants with place of residence and/or business abroad with respect to the individual office, e.g. non-Germans at the German Patent- and Trademark Office.

However, there are several good reasons to seek the assistance of a patent attorney from the first day:

Services of a Patent Attorney

Costs

Generally, patent attorney fees are made up of a fixed base fee and a variable fee that depends on the amount of work.
Some comparative figures about costs are given in: Dieter Rebel, "Gewerbliche Schutzrechte - Ein Praxishandbuch", Carl Heymanns Verlag.
Furthermore, typical costs are reported at "Patent-Pilot" (e.g. costs for the formulation of a German patent application: about 3000-6000 EUR).
Please ask in advance for an estimation of the costs to be expected.