What's stopping you from setting an outrageous price?
It was an other situation, but a lawyer once told me, what happens when such things go to court: The corporation will bring 10 witnesses against you and will bring 10 experts certifying what the corporation needs.
And than you will be very alone and be gracious to get even a little money. You will loose your job anyway.
In general, german courts are quite employee friendly, so seriously, your employer would probably be at least as afraid to go to court as you'd be. Maybe not if it's a litigation-happy megacorp, but the bulk of german companies is medium-sized (Mittelstand) and they tend to shy away from court cases.