There are definitely clinics that give cash patients a 50% discount; I've been to several. The reason is obvious: they get real money rather than a several-month back-and-forth with various unhelpful assholes at an insurance company. That's why the prices are so high to start with. I think that if such a provider isn't careful it can get into trouble with its PPOs, because their contracts require that they get the "best" prices. However, it seems that if a provider is careful it can just say that it has a discount for the uninsured poor.