The Wikipedia article doesn't take in the cost of litigation - it just says that costs vary widely between states. That's true - but a lot of the reason is that some states have passed Tort Reform (which limits the amount you can sue a doctor/hospital, in the absence of gross negligence), and some states have not. Insurance cost varies widely between states as well, because states differ on what they require insurers to cover. Insurance costs more in states where they are required to cover adoption and trans-gender surgeries, for example. And if you live in one state, you can't purchase a policy from another state - that's illegal.
IMHO, if the federal government was serious about health reform, they would have made Tort Reform mandatory, and allowed us to purchase insurance across state lines. These two issues would have driven down the costs for most Americans. But instead, the issue has been politicized.