A lot of pharmacies have a list of drugs they sell for cheap to address this issue. Wal-Mart has a pretty long list of ones that are $4/month or $10/quarter, Costco also has a reduced-price list. Also, ALWAYS shop around for prescriptions. I’ve seen variations of as high as 3:1, and it’s not like the pharmacies always place in the same order for cost. One that was the cheapest on one item might be very high on another. It’s very strange, but you save a lot if you do the work every time.
For example, for every prescription, I call Wal-Mart, Costco, a grocery-store pharmacy, and a couple conventional pharmacies (well on a refill or other prescription I’ve had before I might only call the previous winner to verify current pricing). I don’t think I’ve ever had one of the regular pharmacies be lowest on anything, but there’s no telling whether Wal-Mart, Costco, or the grocery store will come out on top in any given case.