1. The price of anything is determined by demand and supply. Healthcare is expensive because governments increase demand and decrease supply. They increase demand through direct payments and through the tax incentives for third-party insurance. They decrease supply by regulations such as licensing doctors, nurses, etc. and limiting the output of medical schools.
https://mises.org/library/whats-really-wrong-healthcare-industry
https://mises.org/library/how-third-party-payers-drive-medical-costs
2. Here’s a primer on Obamacare.
https://mises.org/library/economics-obamacare
3. Here’s material on free-market healthcare.
4. Before the government began to take over medical services, health care was provided to the poor by charity, either that of doctors, nurses, etc. or by churches and voluntary associations. Take a look at the book by Marvin Olasky.
https://fee.org/articles/book-review-the-tragedy-of-american-compassion-by-marvin-olasky/
5. The links above discuss the single-payer problems.