Our youngish family of four pays $1100 a month on the exchange, which is the cheapest $12k deductible bronze option. This isn't really a FIRE or health exchange problem, it's a cost of healthcare in the US problem. I found out from COBRA that my old mega-corp plan total cost was $2400/month (of which I paid $450), so unfortunately everything is just freaking expensive. It's part of your US cost of living (literally!) whether or not it's hidden in your pay package as a working person or out of pocket as a RE person.
OTOH, there are subsidies that bring that way down for any family in the passive income range discussed on this forum. And if you are earning a bit extra have an income above $100k and end up having to pay $13k/year for health insurance then that's 13%. . . sucks but not the end of the world, and commensurate with the extra tax you would be paying on that money in any country with government healthcare.
It may be wishful thinking, but I would expect the US to nationalize healthcare before I'd expect subsidies to go away. At a minimum it's a very dynamic situation, so it doesn't make sense to fixate on one particular bad scenario. Somehow the country has to arrive at a solution that works for the majority of people, and along the way FIREd people with money in the bank are going to have a lot easier ride than the general population.