You have a PPO plan so you pay a copay. Many people have HSA, High Deductible or Catastrophic plans where they pay out of pocket until their hit their deductible. So all of these people have an incentive to shop on price. You're just choosing to pay more in premiums for the benefit of not having to worry about the costs for care.

But this tool only includes Medicare data so it doesn't apply to any of those cases we just mentioned.

Yes, in the short term. But in the long term, your insurance premiums are decided based on the cost of your health care. So if everyone spent wisely, the premiums would go down or stop rocketing the way they have been.

True, but because you don't foot the bill aside from a relatively small co-pay, hospitals/insurance companies can get by charging more and more. This ruins it for the ~50M Americans who don't have insurance.

We'll see how Obamacare deals with it though.