You'll never, ever find a place where I treated a CBO number as gospel. I work in the defense industry. I know that a cost estimate is always just the starting baseline - things ALWAYS go up from there. Far better for the starting number to be zero than huge, but it's always just the start.
I just can't wrap my head around how these proposed plans are spinning straw into gold. We're essentially intantaneously going to give 40M more people access to health care (massive increase in demand), force insurers to take on pre-existing conditions (which they've never had to), etc, and somehow magically health insurers don't go out of business, health care premiums don't go up, and the deficit comes down. It just defies common sense.
What I actually think will happen instead is that the increased demand for health care services will put such a burden on suppliers that everyone's quality of care will go down. Pent-up demand for services that people had just been living with will be unleashed all at once as people with pre-existing conditions get back into the system, draining the financial reserves of health insurace companies. They also get hit with extra taxes on their high end plans for a double-whammy on costs. To remain solvent, they'll have to raise premiums, causing employers to dump plans outright or increase the costs paid by the employees. The resulting premiums will be high enough that very few plans will be available that are cheaper than simply paying the penalty for not having insurance, so a lot more people than projected will choose to pay the penalty and still head for the emergency rooms for care, so the plan will fail to lead to coverage for anywhere near the advertised 97%. An awful lot of people will end up paying more out of pocket for worse health care than they get today with only a modest increase in the total number of people covered.
If this plan passes, this is one of those situations where I'd be really, really happy to be wrong.