Prescription medicine expenses (copyright Don Farrall, Photodisc, Getty Images)
There aren't coupons for prescription drugs, but Costco (COST) is probably wishing it could print up some "$749 off" inserts right about now.

Consumer Reports went shopping at 200 pharmacies across the country for a month's supply of five prescription drugs that just went generic: Actos for diabetes, Lexapro for depression, Singulair for asthma, Plavix for blood thinning, and Lipitor for high cholesterol.

What they found was a $749 difference -- that's 447% -- between the $916 price tag at CVS (CVS) and the $167 that Costco charged for the same five drugs. For generic Lipitor alone CVS charged $150 to Costco's $17. The generic Lexapro found at CVS for $126 could be had at Costco for $7.

Why such a big difference? Because CVS, Rite Aid (RAD) and Walgreen (WAG) draw most of their profits from the pharmacy, while Costco, Sam's Club and other discount stores consider their pharmacies throw-ins that help bulk up foot traffic.

CVS, in particular, also factors in the cost of drive-through windows, automated prescription refill systems, prescription consultation and 24-hour pharmacies that Costco's Monday-Saturday service lacks.

Americans spent an average of $758 per person out of pocket for medication in 2012, according to a recent Consumer Reports poll. Of the 1,130 people surveyed who regularly took prescription drugs -- both insured and uninsured -- 12% spent more than $1,200 last year.

With CVS' direct competitors pressed to offer the same costly amenities, Rite Aid's price for that five generic drug cocktail is a whopping $820. Even with its pharmacies as a second-fiddle throw-in, Target's (TGT) tally came out to a steep $796 -- a full $360 more than Walgreen's $436.

On the whole, Walgreen fared better than not only its biggest health-and-beauty competitors, but even grocery stores like SuperValu (SVU), Safeway (SWY) and Kroger (KR), which charged $658 for all five drugs. In fact, most prescriptions at Walgreen were only $7 more than those offered at Wal-Mart (WMT) ($426). Only Lexapro cost more at Walgreen ($105) than at the big-box retailer ($84).

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