Shanghainese is a must for anyone who wants to shop in Shanghai and not get completely ripped off. You can look as Chinese as you'd like and that might help a little, but when the words that come rolling out of your mouth are anything but fluent Shanghainese in Shanghai, you can be sure that you aren't getting the best deal you can. I once saw a woman sell my uncle a map for 2 yuan or RMB, then turn around and sell the same map to some foreign toursts for 8 yuan. that's a 400% markup!

Usually when I get dragged out shopping in Shanghai I find it easier to pretend I'm mute and just letting my cousins do all my haggling for me - rather than opening my mouth to speak my shamefully broken Shanghainese. Sometimes the merchants can sense foreigners like a sixth sense and zero in for the kill without you even opening your mouth. After all, Shanghainese are characterized as the most sly people in all China. I will node about the time that being Shanghainese almost got me beaten up in another node... Now I've gotten smart - I say I'm from Wuxi instead when outside of Shanghai.