Maybe the principal investigator Jonathan Mayer [1] should have read his own paper [2] about dark patterns. From the abstract "There is a rapidly growing literature on dark patterns [...] that researchers deem problematic" [2].
Helmut Kohl negotiated a very good deal. Money was not an issue for Germany but speed and total withdrawl of the Russian troops. Germany would have paid much more. A year later and it might be too late for the reunification (Gorbachev was kicked out of the Kremlin).