It assumes you got your donation back from GDC instead of having it transfered to Neo900 UG directly. This way you get everything back except those 13.2% R&D, which ist 13.20 Euros for an initial 100 Euro donation and 26.40 Euro for a 200 Euro donation. To pay the device again (this time to the UG instead of GDC) you have to pay the assumed 700 Euros minus your still valid 13.2% R&D contribution, which differs in absolute amount depending on how much you donated in the first place.