
The real “cost” of it is the administrative cost. Insurance would still be payed just like before, just to the govt under one single program (which would cover all health costs, instead of various networks with different insurance companies). The insurance is already being payed by americans, so that is not a new cost. The administrative cost is likely less than what we’ve spent in the war in iran so far (directly + indirectly)
Medicare for all is govt *insurance* not just free healthcare out of nowhere, and not a universal hospital nationalization like nhs. The administrative cost would likely pay off within a few years. Spreading the risk over such a large pool with single payer insurance and removing the opaque corporate middleman from the healthcare process is financially a better choice. Single payer national health insurance is a no brainer for any advanced and developed country.