A brand new C1 is about 12K€. That's not even twice the price of an electrified cargo bike (I saw about 7/8K€ floated around the other day).
And if you go for used, you can get cars in good enough shape for less than 5K€.
Obviously, the additional car will have a much higher running cost than if you went for an electrified cargo bike or stuck to a single car. Forcing people to make that conscious choice would be a pro in my opinion.
> electrified cargo bike
Hilly area? Taking children to school or old parent to the doctor's? Not a chance!
> stuck to a single car
Yes, the SUV.
Edit:
> if you go for used, you can get cars in good enough shape for less than 5K€.
Yeah, that's nicer. Unfortunately, you have to add insurance and maintenance, plus a parking spot at home. Still too much for people to accept non-tiny cars to be banned from the city.
Mind you, there's only one other family that does it. Most people just walk, some drive.