Healthcare is all free to the patient (the one caveat being a small, fixed charge for prescription medication - which is free for some groups), all paid for via national taxes based on wealth. UK.
If we need a specialist Doctor, we are referred to one. There’s no money involved for the patient whatsoever.
Attaching an unaffordable fee to healthcare would be a clear barrier for anyone who is not upper class, and this would be seen as deeply discriminatory and thus unacceptable.