I use Mark Cuban's pharmacy for a prescription. It's crazy how good their prices can be.
When I started my prescription, I went to a local pharmacy first. A one month supply was $45. But when I looked on Cost Plus Pharmacy, it was $15 for a 3 month supply. And that includes shipping. I quickly changed pharmacies after that.

I shared the pharmacy with friends and family who have prescriptions. They looked into it, but the prices there were nearly the same as what they were paying with insurance. So it wasn't worth for them to switch.
But if you don't have insurance, or insurance won't cover a medication (like in my case), this pharmacy could literally be a life saver.

Edit: rephrasing