lipitor, lexapro, plavix, actos and singulair. another example, cvs is $180, at costco, $15.a gill about the huge difference between the drug prices. >> i have to say, we've been doing this secret shopper survey a number of years and this was the most shocking -- actually, really most surprising results we've ever seen. those price differences do reflect at least two different things. stores use their pharmacies kind of different ways. some stores like rite aid, cvs, they're meant to generate a lot of revenue, a lot of profit for the stores. and that's fine. you kind of see it reflected in high prices. stores like costco, walmart, sam's club, they really try to bring in traffic through having lower prices in the hope that people will buy maybe other things. the other difference, too, is that cvs and rite aid are so convenient. you really pay for that convenience. those pharmacies are open 24 hours a day, seven days a week. they're on every corner in the united states practically. with a store like costco, even though you'll pay such lower prices, you'll have to really plan yo