I have traveled much in China, and it is actually not so good to find good deals. First off, you would need to know Chinese, otherwise you won't ever get a good deal. Second, you have to do a whole lot of looking around to even find what you want. These days a huge number of people in China shop online, and it is where the best deals are found. There are many famous Chinese brands these days however, and you could visit their official stores. That way, you know you would pay the official price, and there is no need to haggle.
Contrary to what the last poster said, we found Shanghai to be a wonderful place to shop! We found some great areas that had everything you ever wanted and then some. We don't speak Chinese, but never had any problems negotiating prices. Most of the time, they speak enough English, so we could understand the cost, but we made sure we had a pocket calculator. If we had a problem with the numbers, we would hand them the calculator, they would punch in the number, then I would multiply it by the currency exchange number in order to figure out the cost in U.S. dollars. Worked great! We just made sure we got yuan (Chinese dollars) from our bank prior to leaving. Once, we had to go to a bank and get some more - no problem there, either.
We even took a taxi over to the main train station and took a day trip over to Suzhou. Rode the bullet train over and back (speed about 200mph). That's an amazing city to visit.
But everywhere we went, we never had any problem with language or prices. Bought some amazing items, ate in some wonderful restaurants, and saw some incredible places. Shanghai is definitely a place to spend a couple of days, so hopefully your itinerary allows you to do that.
__________________ Travel Agent/Cruise Specialist w/15 yrs exp and 50 Cruises on 12 different cruise lines in many parts of the world! VIETNAM VETERAN OWNED & OPERATED. Certified Accessible Travel Advocate. Specializing in unsurpassed personal service to insure you have a hassle-free vacation!