Well just copy paste the Swiss system (of course that’s not feasible both the “free market” and pro “socialized” single payer supporters would hate it). However they have a heavily regulated, reasonably affordable fully private healthcare system.
It dramatically lowered the cost to consumers. Further, conflating overall healthcare spend with the portion of spend tied to a significantly lower-cost population is apples and oranges at best and represents a fundamental misunderstanding of healthcare cost in general. It's ok to not have opinions about things you know you don't understand.