Candy bars for example. They want to charge $3 for a single candy bar now, but no one wants to pay that much so they're selling them 2 for $5. But retailers ha

Candy bars for example. They want to charge $3 for a single candy bar now, but no one wants to pay that much so they're selling them 2 for $5. But retailers have studied that this trick isn't going to last because not everyone wants to buy candy bars in bulk, and they won't spend more than $3 for a single candy bar, which means if it goes any higher they won't by any candy bars at all.