With the holidays around the corner, some Canadian shoppers are looking south of the border for bargains. But when comparing prices on U.S. retail websites, it's not just the exchange rate you have to calculate. Shipping and handling, brokerage fees (the cost of the shipping company acting as your agent to clear your goods at the border), and in some cases, duties have to be paid. Not to mention your province's retail sales tax. Below, Preet Banerjee gives one example of how to crunch the numbers to see when you're saving money buying from a U.S. retailer online. Depending on what you are getting, you might be better off buying locally.