This folk wisdom is really nonsense. We renovated a house in 11 weeks. Including complete electrical installation, both bathrooms, water/sewage, floors completely sanded, leveled and newly laid, radiators and completely wallpapered. Also central heating on gas including connection, roof insulated and so on and so forth. Only most of the windows and interior doors remained. Investment: time and a total of about €240k for a renovated house of 140sqm, basement, triple garage, cold winter garden, 1000sqm plot with automatic irrigation and lawn mower robot. Everything grown around. At the back of the property there is a new development area where the square meter goes for €120. The whole thing in the further commuter belt of Hannover. About 35km. So not the worst location. Doctors, schools etc. all there. I work in the federal administration. I have never trained for anything else. You need some talent, self-confidence and have to be able to coordinate and plan. Luck is also part of it. We now have a moderate rate well under €1000 per month and can send both children to nursery/kindergarten without having to make sacrifices.