I absolutely would love things to be transparent, but I think healthcare is more like fixing software bugs than delivering well-scoped features. It's very hard to estimate anything beyond the most basic, superficial issues.
Just to be totally clear, I want prices posted online. I'm just worried there would be asterisks next to everything and then they would be useless. Perhaps that's an opportunity for differentiation in hospitals: "broken bone - cast set: $X - all inclusive".