Store owners in New Brunswick are nervously wondering how new cross-border shopping rules will affect their bottom line.

Starting Friday, the duty-free limit has increased from $50 to $200 for a 24 hour visit to the United States. People spending 48 hours across the border can bring back $800 worth of goods – double the old amount.

"My first thought was the government’s not helping business with this step," said Sharyn VanDerGulik. Her store in St. Stephen is closing down in a few weeks, in part because she’s losing her customers to stores in nearby Bangor and Calais, Maine.

"Being in business in a small town with a small business is tough enough as it is. When the government’s working against you, it makes it even tougher."

Cross border shopping is big business for American retailers. An estimated $20 billion Canadian flows south every year. The new rules could bring that figure even higher.

But John Quartermain doesn't think it will make much of a difference in St. Stephen. The retailers in the bordertown are used to shoppers heading south.

"It seems to be a culture that's gone on here for a long, long time. As long as I've been around, anyway," he said.

Kevin Stuart, who owns a gift store, said he believes the cities – Saint John, Moncton and Fredericton – will notice a difference.

"Because they have a lot of people who shop on the American side on a weekly basis," he said. "It just means that instead of them coming for a day, maybe they'll come down and spend a couple of days. You're going to see more and more of their money go across the border."

The federal government said the limits are being increased so customs agents will have more time to focus on border security.