If you are looking for calligraphies, porcelain, antiques you have to go to the PANJIAJUAN market in Beijing. It is only on the weekend and you have to go there early, but it is the biggest market in Beijing. The size is about 4 football fields filled with people selling everything possible. And because there is such a big offer the prices are fine. Of course you have to keep in mind that there is a tough bargaining necessary. It`s part of the Chinese culture (like in Morocco or many other countries). A simple rule for a beginner is always less than half of the price they offer to you as a foreigner or lowai they say in Chinese.Advanced traders knock prices down to a third of the original price, it depends(keep in mind that vendors try to get moonprices so actually it is often just a tenth of their original price). Bargain is a part of Chinese life, it is not offending towards the trader. Everything is negotiable in China. As long as they still sell it to you, you can be sure they have a good profit. And it actually is big fun for you and the trader.
An example:
A handpainted calligraphie with a size of 190x70cm, with so called silkpaper and a wooden roll, sometimes covered with porcelaine endings should be less than 80 kuai. Check with hands and eyes that it is no print!!!
Without wood roll you get the same size for 20 Kuai!
When they pretend that they don? want to sell it for a certain price - leave them. They will come after you to bargain again. If you do this process two or three times you will get the right price!
For a good bargain you need time. Never be in a hurry.
(Chinese friends checked prices, too. They didn? get it much cheaper)

How to get there:
Take Metro Line 1 from the ForbiddenCity/Tiananmen for 5 stations and get off at GUOMAO Station. Outside the station take Bus No. 28 for 20-25 minutes to the market. Just ask people on the bus, they know the market.

If you are looking for cheap clothes, technical equipment and fakes you should try the HONGQIAO market which is inside a big building with three or four storeys. It is situated closer to the Temple of Heaven. From there it is easy to reach by bus, changing lines once.
An example:
A "real" fake of Lacoste or Ralph Lauren Polo Shirt should cost under 30 or 40 Kuai in the end, never pay more than that!
Oh, and never believe something is real;-)

The ANTIQUE MARKET is situated in Yuzhong District, downtown Chongqing, close to Jiefang Bei. From JiefangBei walk down the MinquanLu to the round about or rotary traffic meeting the XinhuaLu (10 minutes walking). From this traffic circle you take the second street on the right side, which is called ZhongxingLu and heads down to the ChangJiang
Walk down this road where the Tea House is situated (my first tip) for maybe 5 more minutes. On the left side you will see a big building, which you can not miss because of many busy people. It is not spectacular from the outside but there are at least three floors full of traders. From the street you would enter the third one which offers electronic stuff, but I was not looking for a tv or washing machine. Walk around the building or down the stairs to the first two storeys where you can only find antiques! And by the way they where looking at me you could tell that this is a real Chinese market where they don? see foreigners very often (even in Chongqing). They offer everything from little things to complete old traditional Chinese beds and wooden statues (looked like old temple statues) of more than 3 meters height. You name it, they got it!
This market is open everyday, but don? come too late. If you come by on the weekend there is also some market outside offering all kinds of goods.

Have a good price hunting!