Evaluation of Photovoltaic Offer

The offer is about 8,000 - 10,000 euros too expensive. What are electrician costs of 3,000 euros charged for? Surely not for the 2 hours of work on the meter cabinet.

It is simply the price of a solar installer. They just build the systems at that price. Considering the shortage of providers, such prices can indeed be enforced.

Just offer the solar installer to buy the components themselves. Then they won't install them.
I also had great offers from various solar installers who absolutely wanted to install Fronius inverters in connection with BYD batteries.
And only this system. Unfortunately, the price was very high at that time and nothing could be delivered. I then realized it myself with the Huawei system.

Good idea to take out the Wallbox first. I think it makes sense, who knows what will come in a few years

As long as you do not have an electric car, which is usually charged in the evening or at night, the storage, especially in this size, makes 0.0000 sense. By the way, the next generation of electric cars could already be the one that has decent batteries and then completely replaces the storage.

The next generation of electric cars could, by the way, already be the one that has reasonable batteries and completely replaces storage.

They already exist today. All new ID models from VW with the 77kWh battery can do that - however, there is a lack of hardware choices such as wallboxes, etc.

Are German components such as inverters from SMA not an option? If only associated with a small surcharge, I would always prefer German or at least European components in the interest of all of us. We harm ourselves economically by buying even more Chinese products and thereby can offer them at even lower prices through economy of scale.

They already exist today. All new ID models from VW with the 77kWh battery can do that - however, the hardware selection such as wall boxes is lacking.

A decent battery enables a range of more than 1,000 km under WLTP and charges from 10 to 80% in under 30 minutes. The Japanese are working on something like that; Toyota aims to have the solid-state battery production-ready by 2027.
The garbage that VW and co. are currently installing in their cars, let's call it at best the early beta version.

Bad enough that I will get such a thing as a company car in a few days...