I haven’t read the construction service description in detail, but from my perspective, there is little (if anything) "upscale" – it’s quite basic equipment, especially since besides the material, the service is quite limited. The example with the tiles is quite nice. For 18,- EUR you only get basic models at the wholesaler as well. If you can live with that, fine. Otherwise ... not so cheap anymore.
In our contract, tiles up to 40,- EUR/m² were included. That covered us for bathrooms, kitchen, and hallway (taking into account lower tile height, omission of tile backsplashes, etc. ... speaking of tile backsplashes! Ah, whatever ...). But the living room was significantly more expensive ...
The sockets/switches are also quite minimal. I didn’t read about a single two-way switch. Meaning: You have *one* switch for the hallway on the ground floor and one upstairs. Practically, we had a total of four (for downstairs lighting and upstairs lighting). No telephone let alone network, ... I’d say you can easily add another 20,000,- EUR for your special requests and still be far from "upscale." Believe it, or just blindly run into your biggest adventure – although building a house itself is already a big adventure.
Cheers
K1300S