Driver’s license A2

Since January 2013 the laws for driving licences have changed. Who has the old A1 for at least 3 years, can acquire the A2 by only taking the practical examination (and of course exists). I now have the old driver’s license 3, which includes the A1 (up to 125ccm). For three years I drive a BMW C1 and want to switch to the BMW C1 200. A demand at the TÜV resulted: you can only register for the test via a driving school! d Fee for registration for the exam. I should also take some driving hours. Danaben is the actual exam fee of ca75,-€ a crack. I have the feeling I should be excluded. Does anyone know a cheaper way?