Rough estimate of renovation and modernization costs

We have now, after a long search, identified a multi-family house.
- Three residential units (75, 75, and 50 sqm)
- 10x10m footprint of the house
- Gable roof with 45° pitch

How much should we roughly budget for the following items?
1. Re-roofing the roof
2. Insulating the roof
3. Replacing gas floor heating systems with a gas central heating system
4. New electrical system
5. New pipes/wiring
6. Renovating three bathrooms
7. Relocating two to three doors

Rough estimates are sufficient so that we can include this in the purchase price.

So basically a complete renovation - only new windows and floors are missing. Would guess around 600-1,000 € per sqm, depending on the desired quality and the craftsman prices in your area.

Depends on where in Germany. Roughly estimated, I would say around 150,000 euros. It becomes difficult to get craftsmen for that.

The roof could also be done later. It is not leaking, just not the newest anymore. Insulation could also be done by ourselves. With the bathrooms, one could also do a lot by oneself... Better to keep our hands off the electrical stuff and all that nonsense. Would about 100,000 be realistic then?