hi i would like to travel to yiwu from hangzhou airport

Well, according to your arrival time, there is no bullet train to Yiwu on the same day. Thew earliest one in the next morning leaves at 06:35. So you can find a hotel nearby the railway station, and start off in the next early morning. And the cab fare from the airport to the East Railway Station (high-speed trains) is CNY120 or little more at that time. Anyway, the first class seat costs CNY84.5 and second class seat costs CNY50 by bullet train.

Maybe it's not easy for you to find a taxi to Yiwu that latem so it is best to hire a car in advance. Generally speaking, the fare is CNY250-300.

There is the third option. After arrival, you can find a hotel nearby the airport. And in the next morning, you can take direct long-distance bus to get to Yiwu. The bus schedules are 10:20 to 21:30 with the interval of 40 mins. The duration is about 2 hours. The ticket fare is CNY 62 per person.

Thank you jacob.. My flight now delayed. I will arrive in hangzhou at 1.30am. How about the taxi charge/fare after midnight?

At that time, hiring a private car is more practical. The fare would be a little higher than day time. It cost CNY 300 to 400. Or book a transfer service in advance. Search Ehi Car Services to ask if offers transfer of this route.