Retailers are getting away with highway robbery by selling certain individually-packaged items (small batteries, car headlights) for a few cents less than dual-packaged items, essentially convincing people to buy the more expensive but more economical double pack.  For example, the double pack of watch batteries I just bought cost something like $4.50, while the single pack cost $4.  Any idiot can figure out that the double pack is a better deal, but I have a feeling the price of the single pack is artificially inflated in order to force customers into buying more than they need.  And even though the customer is getting a better deal, they're still spending more money than they need to, which of course benefits the retailer. #business