Does this electrical system need to be renewed? (Condominium, 1960s)

Yes? I would have expected well under 10,000 euros.

Get some concrete offers, you will see. In 2017, we paid about 11,000€ at the cheapest provider for 88m2 of living space in a simple execution. And they only had that price because the apprentice did almost everything. Sure, you can save something here and there by doing the chases yourself, yes, but that doesn’t make a huge difference. But it simply costs that much.

ok, thanks, I will get concrete offers.

For a new sub-distribution and a few new cables+sockets?!
How do you come up with such a high amount?

Because in such a condition you should do everything at once. What’s the point of only partially replacing things? The place is completely run down anyway, everything new at once. In other threads there are still some pictures that support this impression.

In the case of a partial extension/modification of the electrical installation, it can quickly happen that the "grandfathering" of the existing electrical installation is overridden, and thus the electrical installation as a whole *must* be brought up to the current state of the art (RCD etc. - which is always advisable). Therefore, there are basically only two sensible options: do nothing, or carry out a complete new installation.

Above all, the person who operates a device with a Schuko plug where the wires are visible, meaning there is no strain relief of any kind, should be warned.

Grandfathering basically no longer exists when the system is expanded.

Whether you can chisel yourself depends on the electrician. If he says he will do it or not at all, then that’s how it is ;)