Shopping is a mixed bag in Vietnam and a large part of its appeal lies in the challenge of purchasing what you want and to buy it at the price you think it should be. Unfortunately, as a foreigner, the chances of being charged 40-50% more than locals on any goods or services throughout the country (this rate tends to be even higher in Bến Thành Market, up to a solid 100% more). Having a Vietnamese friend with you may help, but the sales person will generally see through the ruse and overcharge you accordingly. Other shopping tactics include finding the price of the product you’re after through friends or online before even leaving the house, and browsing the whole market complex before buying to see if anyone else is selling the same product at a cheaper price.
Another important aspect of shopping in Vietnam is bargaining. Before you ask the shop owner how much that shiny postcard is, mentally decide how much you are willing to pay for it and then offer about a third of that amount. The idea is that you will eventually meet in the middle, ending up with a win-win situation. As a last solution to getting desired goods for a reasonable amount of money, pretend to leave without buying as this will usually cause the vendor to call you back to agree on your stated price.