I'm not sure how people do it either, but understand if your income drops way down. If we retired now, pre-age 62, we'd pay for premiums of around $1k per month, and max O_O_P of around $12k per year. Of course, we're in our 50s and have 4 children to cover.
Once again, the price you are seeing is the cost prior to subsidies. As an example, I just looked up quotes on my state's marketplace for a family of six: married 50-year-old couple with four college-aged kids. The second-cheapest silver plan was pretty similar to the plan you're talking about: $5,500/11,000 individual/family deductible, $6,500/13,000 out-of-pocket maximum, $973 monthly premium. Super expensive, right?
But if you report an income of $60,000 (just under 200% of the poverty line for a family that size), you get a $674/month tax credit, bringing the premium cost down to $299/month. Also this income is low enough for the cost-sharing subsidies, which drop the deductibles all the way down to $350/700 and the out-of-pocket maximum down to $2,250/4,500. This is a much more manageable cost, and all you have to do is get your taxable income down a bit.
Even if you don't think you will be able to
spend less than $60k before your kids leave the house, it's entirely possible that your retirement
income will be less than this. Note that HSA withdrawals and the principal portion of taxable investment withdrawals and most Roth withdrawals don't count as income for this purpose.