Planning to travel. how much would we need to cover all expenses?

Sarah, she'd better make a plan in advance, which should cover where to visit, what requirements she has toward food, accommodation and transportation means. Otherwise, it's really difficult to estimate how much money she should carry.

Personally, she needn't bring much cash. According to the law, she can take as much as 5000USD or 20000 RMB in cash. But this isn't a problem. She can withdraw money from ATMs after she arrives.