moondog

If I were in your shoes, I'd probably jailbreak one of your iPhones instead of buying a y150 phone, but both tasks can be accomplished at the same stores. Buy Now is the closest to Wangfujing that I know of, while the market near Chef Too (Chaoyang Park, west gate) is the cheapest (assuming you don't want to make the trek to Zhonguancun). There are also lots of cell phone stores in Wangfujing itself; you will not find a Y150 phone at any of them, but they can do the jailbreaking drill for a small premium over the guys at Buy Now.