I hadn't realized there was such a difference between cash price and prescription price.

Through work currently we can use a web site to help find your cheapest place for prescriptions. One bottle of Novolin R like you said about is about $25 from Walmart for cash price. One bottle of the same prescription with a discount coupon is $138 dollars.

That's still cheaper than Novolog/Humalog, but how in the world is it more expensive to buy insulin with a prescription and insurance than without? When I pay a 20% co-pay am I essentially paying my insurance company the extra money?