House 2 years old timber frame construction

House could have poor sound insulation since it is a prefabricated wooden house from Massa Haus. Maybe that's the reason for selling? Otherwise, no idea what could stop you from buying.

The house seems to be so close to the optimum for you that if I were in your position, I would try not to worry about a few euros more or less.

What is going on with you? Either you buy it or someone else does. If the latter, then you keep searching for more years. Some things cannot be calculated with 10/20 00o, some things cannot be compared with 10/15%. Some properties are available now or never again ... for you, your generation, today's time. The next suitable property will be snatched away by someone else... It may be that you pay an extra 10,000/20,000 including. That's nothing when you consider everything. You have to be satisfied.

Some objects exist now or never again

That's exactly right. Keyword "one of a kind".

It may be that you pay extra including 10000/20000.

Pay extra on what at all. It's all very hypothetical.