All of which goes a long way toward explaining the recent success of dollar stores. In November, for example, Dollar Tree, the largest chain that sells only $1 items, reported quarterly net sales of $1.6 billion at its more than 4,000 locations in the United States and Canada, up nearly 12 percent from the same period the previous year. And last week, Family Dollar, which has a whopping 7,100 stores in 45 states and carries items with prices that can reach the double digits (a $35 home music system, too rich for my blood), reported that it had set a new record in the fall, with more than $2.1 billion in net sales of what it calls “a mix of name brands and quality private brand merchandise.”

A good chunk of that “private brand merchandise,” of course, comes from China and India, which are home to huge suppliers of dollar stores, not to mention some questionable manufacturing methods. But spokesmen for both stores insisted that the goods are safe (meaning they’ve been tested for lead) and were produced in humane working conditions.

“We want to work with organizations that treat their people well and take care of the environment,” said Joshua Braverman, a spokesman for Family Dollar. And while he acknowledged that the company’s “global sourcing program” partnered with factories around the world, Mr. Braverman patriotically insisted that “a majority of merchandise is from here in the United States.”

But there’s also plenty that isn’t. Take the Cristar line of glassware that I found — and bought loads of — at Yankee One Dollar, a chain that operates 32 stores in New York and Vermont. The glasses, which are simple, solid and decidedly unsexy, are imported from Colombia in shipping containers and then trucked upstate.

The national chains may be thriving, said Keith Flike, the owner of Yankee One Dollar, but increases in costs to transport such containers, as well as price increases passed on from overseas suppliers, are threatening regional dollar stores like his own.

“Last year, the Chinese raised their prices 15 cents on a bunch of stuff,” Mr. Flike said. “And 15 cents when you’re selling for $1 is a big chunk of profits.”