I am from Germany, I was billed like 700€ for a small checkup in a hospital in France because of an infection in my mouth after an operation. They first couldn't find me, because they didn't write my address right. so I had a collection agency writing mean letters to me, wanting more money.

I gave it to my healthcare provider and they sorted it out and paid it without questions ✨

This is just off the top of my head, so the numbers are approximate.

In France it's (of course) a bit complicated in that you often pay first and then get partially reimbursed by the state system. If I go to my doctor and get a prescription, I'll pay about 20€ for the consultation + about 8€ for the medicine, no matter what it is, but will have about 70% of that paid back to my bank account later. If I were to go the hospital and have to stay overnight, I'll get charged a considerable amount for the treatment, medication and the hospital bed (and have that also partially reimbursed). However, there's a sliding scale of cosmetic to serious treatments that are reimbursed at progressively higher rates. This means you pay more for trivial stuff and less for important stuff up to life-threatening illnesses (e.g. cancer) for which the treatment is free (I think, I've not had one).

I pay around 8% of my annual income in health tax. Most people pay extra for private medical insurance (around 50€ a month, typically) in order to have all costs fully covered. The insurance companies are strictly regulated and pay out. I had a tooth pulled and it cost me 8€. If I want to replace it with an implant, it's 800€.

France is complicated.

In the UK there's usually no charge at all for a consultation or hospital treatment. Prescriptions are about £9 per item, no matter what the drug is. I pay approximately 11% of my annual income in health tax. Some people still pay extra for private health insurance in order to get preferential treatment and increase the inequality.

The above applies to residents, not to visitors unless their country has special agreement with the UK or French governments.

source: I've lived in both countries and I've almost bored myself into a coma by typing all this unnecessary detail.