It lasted one hour only, without any pause. I kept my position : cancellation of sale please. Nobody caved in. Some vaguely talked about giving some money, hardly enough to cover the reparations to come this year. They thought money was above everything, so this was not an option for me at all. The guy from the housing agency was very off-hand and disgusting. The ex-owner played the ignorant.
So there was nothing to agree on. Time for a trial. This will last several months/years, and I may be a loser in the end, even if I win it. I'm keeping the appartment of course, and will probably end up there during all that time.
