Depends on your traveling style. You can travel in China for as little as US$30-40 a day including accommodation, transport and food. This would include staying in hostels, catching public transport and eating local cuisine.
But to travel five-star, you can easily spend US$100-200 per day, easier in cities such as Shanghai.
The best cities for trading would probably be Shenzhen and Guangzhou in the south of China.
There are definitely travel agents, guides etc. for hire. about 7 years ago