That is fair. The distinction is between not having records immediately to hand and refusing to clarify whether they exist. The former can be workable; the latter is a reason not to spend more time.
It would help to set expectations for the next step: suitable summaries receive a request for supporting information, then a viewing discussion. Unsuitable approaches get a quick decline rather than prolonged document exchanges.
Has the search produced any credible candidates, Hugo? If not, the unanswered points seem to be whether 165 m² is internal area, whether Munich city proper is mandatory, and whether €289,800 is purchase-only or all-in.