It's gotten better with the beginning of the federal marketplace, but it still is true that better coverage is gotten from a full time job. Though, I guess it depends on what you are looking for. I pay $350 a month for a decent plan in Chicago. But, I'm a mostly healthy 30 year old so YMMV.
Some options you might consider for further coverage:
1. Have a spouse that has insurance. Easy mode, but seems to be an option for some people.
2. Part time job that has benefits. I have a friend doing exactly this - 20 hours a week working at a university and the rest of the time freelancing. Provides a little human interaction too.
3. Medical tourism? I only half joke that I may up and go to Lithuania if I ever need not urgent major surgery (though I might do that even with good insurance). Being freelance opens up that option.
But as more and more people become freelancers, I have to imagine this situation will change. I really hope that in the next 10 years we'll get more options, whether full fledged socialized healthcare or even just the ability to get the same plans as employees. If you were needing a reason to vote in the upcoming elections this is probably the one that most directly impacts freelancers.