You'll also notice many drugs have generic versions, which sell for pennies on the dollar, comparatively to their non-generic productions, something I deal with all the time. I've an aging family member who's required surgery about 8 times over the past 2 years, and almost every prescription is written out for a brand name drug, despite the fact generics exist. It's the difference between a few dollars to $800. Typically, the generic producers get around the patent law by producing a version with a slight alteration in dosing by .0001, depending on the drug. The problem is, most consumers aren't aware, nor do they act like a rational consumer, because A) they either have insurance, or B) they're utilizing Medicare or Medicaid. They're spending other people's money, so they don't shop for the lowest price. Thus, they have a negative impact on pharmaceutical markets, as they don't ensure competition. If it weren't for this, you'd be looking at pharmacies selling drugs as low as their production costs.
