If you read the original post, i'm asking could i have got away with less than 100zl, for future reference.
You could always drive within the speed limits - that is also an option. Maybe for future reference that is the way to go?
I got fined in February for speeding as well - only felt irritated I had to pay on the spot.
But as Delph explained - I was lucky, by this way it did not cost me any points.
Got a nice receipt though :)