The way our healthcare financing system is currently designed there is no way to achieve price transparency. A hospital is like a market stand where everyone barters over the price. Hospitals barter with insurers, which creates a multitude of different reimbursement rates. Hospitals then often have to also barter with the insured patients regarding any out of pocket expenses (co-pays, deductibles, etc). Hospitals even barter with uninsured patients over what they can and can't possibly pay. When you put all this together there is no "actual price," the hospital is left bartering for whatever it can get with hundreds or even thousands of different parties. (i.e. the market stand analogy)
Even if hospitals provided a "price" it wouldn't provide price transparency. Approximately 85% of people have insurance, with that number expected to increase under ACA. The hospital price wouldn't tell you anything about what your insurer is going to reimburse at. If you want to "price" shop you would need to know your insurance reimbursement rates for various hospitals, not the hospital prices. That is the price being paid, and thus the actual cost. What is being demanded (hospital pricing) doesn't provide the information need, and still makes for poor consumer choices. Here is an example of what I'm explaining:
Example: Hospital A could post a price of $100, while Hospital B posts a price of $110. Consumer would assume that Hospital A is cheaper. However their insurer may reimburse Hospital A $105, while Hospital B is only reimbursed $100. At which point the consumer would be actually costing more.