The grocery store has a legitimate reason to sell milk for $0.99...it's because they know from experience, that once they have you in the store, they, on average, will make up the loss because you buy more than just milk.
I don't see how that works with prescriptions. It's not like if I get a prescription that's manufactured by PharmaX, that means I'll somehow end up buying more from PharmaX. If I'm missing something about the business model, fill me in, but I don't see any motivation that a drug maker would willingly sell a drug at a loss. In other words, if CountryX came and said "The most I'll give you is $1 per pill" and your COGS is $2, why wouldn't you just tell CountryX to take a hike?