Costco prices
According to this New York Times story on Costco:
"When I started, Sears, Roebuck was the Costco of the country, but they allowed someone else to come in under them," he said. "We don't want to be one of the casualties. We don't want to turn around and say, 'We got so fancy we've raised our prices,' and all of a sudden a new competitor comes in and beats our prices."
At Costco, one of Mr. Sinegal's cardinal rules is that no branded item can be marked up by more than 14 percent, and no private-label item by more than 15 percent. In contrast, supermarkets generally mark up merchandise by 25 percent, and department stores by 50 percent or more.