Single-family house from 1950 with backlog of renovations "Charm of the 50s" - renovation costs

Regarding the house, if one can say that…
Unfortunately, you probably don’t have any own photos of the structure, corners, etc? (Link has been deleted)
As a former real estate photographer, I would digitally retouch any blackening on the walls, remove some algae from the roof, and prepare everything a bit for marketing purposes.
Well then: I’d say: whoever is looking for what the headline promises will find it as well. The house would lose its charm if you renovate too much or go about it the wrong way.
Gas heating is from 2010. Plastic windows with shutters from 1980, wooden floors are great. What I would do: replace the electrical system, bathrooms, and carpet floor coverings.
Possibly have the flat roof extension checked for watertightness, as well as the energy calculation.
Underfloor heating or later conversion: ask an energy consultant.
But first involve an expert.
If you replace the windows, you probably also have to address the facade.
Consider a larger window towards the garden.

A little update:
So what definitely has to be done is all the electrics (including installing new sockets and distribution board / fuse box), 2 bathrooms new, one of them enlarged, there is carpet everywhere but “still good” wooden floorboards underneath (could be refurbished). Roof still good, but uninsulated, a few cracks here and there (since the owners never did anything major, we see these as uncritical, possibly just repairs), basement not damp but uninsulated. Gas heating old, still works, heating pipes etc. unfortunately installed outside, so visible in the living area, windows so-so, but possibly still salvageable, since thick.

For the year it was built and since nothing major has ever been renovated, it was surprisingly in good condition.

What do you think, where could the price range go? Thanks!

[*]Roof: above-rafter insulation and new roofing: e.g. 60k
[*]Exterior insulation 35k
[*]New windows 25k
[*]New front door 3k
[*]Renew heating
[*]Replace radiators or remove screed and install underfloor heating?
[*]New electrics (chiseling channels yourself saves money)
[*]2 bathrooms, 1 kitchen: 25k+
[*]Floor coverings including installation
[*]New staircase? New wallpapering?

Make a list of all the points that need to be done and look up prices online for each and add them up.

[*]Roof: overlay insulation and re-roofing: e.g. 60k
[*]External insulation 35k
[*]New windows 25k
[*]New front door 3k
[*]Renew heating
[*]Renew radiators or remove screed and install underfloor heating?
[*]New electrical work (chasing the grooves yourself saves money)
[*]2 bathrooms, 1 kitchen: 25k+
[*]Floor coverings including installation
[*]New stairs? New wallpapering?

Floor plan fits, or do walls need to be moved as well?
Have roof windows installed?
There probably won’t be any money left for photovoltaics, maybe at least lay the connection to the roof for later.
Renewing the heating without insulating the facade makes little sense, because after insulating your heating will be oversized.

A year ago I made such a list and asked for prices by phone to see if the rough scale was right.
And watch out for real estate agents, mine said "yeah, our architect says with 200k you have the thing top-fitted here." When I asked again he said "no, he calculated with insulation under the rafters, the roof is still fine." That was older than yours. So the architect's calculation already missed 40k.

A few more questions to the group:
Renovate an old building, or an alternative? Do you even have to insulate an old building with thick masonry (keyword room quality and mold formation)?