The cognitive dissonance confronting people who hate Wal-Mart (NYSE: WMT) but lament the cost of prescription drugs is growing stronger.

In a press release on Monday, the retailer announced that "Beginning today, Wal-Mart, Neighborhood Market and Sam's Club pharmacies will fill prescriptions for up to 350 generic medications at $10 for a 90-day supply." Wal-Mart is also adding adding $9 generic prescriptions for up to a 30-day supplies for drugs treating osteoporosis, breast cancer, menopause and hormone deficiency, in addition to a new "$4 OTC offering," consisting of more than 1,000 products available without a prescription priced at $4 or less.

According to Wal-Mart, roughly "95 percent of the prescriptions written in the majority of therapeutic categories are included in the $4 Prescription Program." In the less than three years since it launched its cheap prescription drugs initiative, Wal-Mart estimated that it has saved consumers over $1 billion on health care.

But wait, there's more! At 7:26 PM EDT, Target (NYSE: TGT) responded with a press release stating that "As part of its ongoing commitment to provide exceptional value to guests and consistent with prior practices, Target will reduce prices on its prescription and over-the-counter drug offerings, remaining competitively priced with Wal*Mart."

Like most price wars, this one looks to turn out well for cash-strapped consumers.

But a word to the wise: part of the reason Wal-Mart and Target are doing this is that they want you to wander around and shop while you wait for your medication. So if you use a big-box store's pharmacy, bring a book or magazine and pull up a chair -- the savings will be nullified if you walk out of there with a $4 prescription and $30 worth of crap you don't need.