Comment by AnnaPali
Christian healthcare sharers do precisely this. By restricting services and the population addressed (your pastor or priest must sign off on your application), everything's extremely affordable. In particular, as we don't drink, do drugs, use contraceptives etc. we don't pay for coverage of them or their side effects. Obesity's also less of an issue.
There's also the trick of telling the hospital you'll pay "in cash" and getting a 10x lower bill from the hospital, then getting that reimbursed/covered by your private or alternative insurance.
Christians don't drink or use contraceptives? I think you have to have a pretty extreme "no true Scotsman" attitude to make such a claim. Even the drugs claim is pretty specious.