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

Hello everyone, we have the opportunity to buy a house in almost our desired location (2 plus).
About the property: around 1950, approx. 150 sqm, plot approx. 500 sqm, solid construction, currently a single-family house, but separated by a hallway as it was built as a two-family house, the equipment of the house is based on the year of construction: wiring, electricity, roof...

Of course, we are deterred by the uncertainty of renovation costs. And the long double burden (rent plus loan), since the renovation would certainly take about 6 months (or more).

The question is, how big is the risk? Should one currently avoid such large projects and does anyone have a ballpark figure of what a renovation could cost here.

Thanks in advance! :)

No one has anything to say ;) … I’m grateful for any assessment

Well, I’m not familiar with Lower Saxony’s construction prices. ;-)

What did you want to have done? And what do you plan to do yourself?

I would definitely expect the total duration to be longer than 6 months. Finding craftsmen, getting them to make an offer, waiting for the materials to arrive – that can take a while.

Well, I am not familiar with construction prices in Lower Saxony. ;-)

What did you want to have done? And what do you want to do yourself?

I would definitely plan for a total duration of more than 6 months. Finding craftsmen, getting quotes, waiting for materials to arrive – that can take some time.

The house is about 70 years old, I assume we would have to do everything: electrical, water, roof, windows, heating, bathrooms, kitchen, insulation (company or privately) Or do you think that some things, despite the age, could still be repaired?

Small things like painting etc. we could do ourselves

Everything new?
I throw a slim 300k into the ring. If you find materials and craftsmen and an architect.

I assume that we would have to do everything:

Well, you don't say a word about the current state: heating, windows... Who can say anything about that???? Get yourself a building expert, who has been recommended here for years... that before the purchase... at the latest before calculating the renovation. Our crystal balls have fog regarding unknown objects.