At Costco Pharmacy I stopped using my insurance plan as the co-pay was more than the no claim cash price. I learned later that my health insurance company owns its own pharmacy and they design the claims process to bias you toward their own pharmacy. Since medical loss ratio must exceed 85% on employer health plans they realize their excess profits by jacking up prices at their pharmacy subsidiary and using their pharmacy benefit manager subsidiary and insurance product to steer you toward overpaying if you just take their suggestion (e.g. $100 if you use OptumRX mail order Pharmacy for the "savings" versus $20 cash price from Costco).