I've been told that insurance pays a negotiated rate of around 15 to 25 cents on the dollar. So for example if your co-payment is 20%, you are actually paying the full amount of real medical costs, while your insurance co pays nothing.
The reason reason hospitals inflate costs, is to deal with these huge discounts
To make things worse, the uninsured don't have a negotiated payment percentage, so they are expected to pay the full amount of these inflated costs.