How much roughly do you pay per month for these German and French models?
I'm not sure. It's not cheap. A bit of Googling suggests that the social security system costs about 3000 euros per person, which is obviously going to be massively skewed towards higher taxpayers. Most people then have health insurance on top, which is not compulsory but generally ensures that you get all or almost all of your medical costs back. (When you pay to see a doctor, a certain amount of what you pay is reimbursed by social security, and the rest is up to your health insurance provider.) I pay 50 euros a month for my health insurance but I haven't shopped around so I could probably get a better or cheaper policy.
People on low incomes have additional health insurance which they don't pay for.
If you include a likely tax increase to match health spending and a basic health insurance package I would imagine most households would be at least £100 worse off a month
I genuinely don't know. It's really hard to compare. And between the two countries, some things are more expensive in one country and some things are more expensive in the other, so you can't really isolate something like healthcare. The energy price increases have been capped by the French government. Rent can't be put up at the will of the landlord. Mortgage borrowing is massively cheaper in France. But you pay to use motorways, petrol is more expensive here than in the UK now, and food and clothes are more expensive.
think about the impact the gas price hikes are having on families with this kind of extra expenditure - all the threads on here about food vs heating ....And does it end up being like car insurance when you pay most things your self anyway to stop your premiums rocketing ?
No it doesn't. That's not how it works. And a lot of the time the most serious illnesses are completely covered by social security anyway, such as cancer treatment for example, so your health insurance doesn't come into it other than for things like if you want a private room in hospital.