Got my eyes opened when one provider offered to bill me $500 via insurance or $180 cash.
That has not been my experience. Rather, many doctors have a cash "rack" rate that they then negotiate down to the insurance reimbursement rate that they have negotiated with their insurance carriers. In fact, the agreement between the medical provider and insurance carrier often prohibits the medcial provider from charging a lower rate to cash customers and if the provider is caught (under the agreement with the insurance carrier, the provider is subject to audit), then the insurance carrier may assess liquidated damages against the provider and reduce the insurance reimbursement rate to the lower cash rate going forward.