Entry fee into the city is RMB 100 per person per day. This ticket gives you entry to the ancient city area. Without purchasing the ticket, you cannot enter the area.
There is an organized boat ride down the narrow canal. It costs ~ RMB 40 yuan per head, or ~ RMB 100 yuan for a boat, which can be used by 1-6 people. The boat ride lasts 20 minutes.
If coming from Shanghai, you will also need to rent a mini-van (up to 6 people) or car (up to 4 people) for the day, adding ~ RMB 1200
Plan for a full day (8 or 10 hours vehicle rental return trip) leaving Shanghai in morning and returning late afternoon. Leave a buffer of time in case of bad traffic on the highway returning to Shanghai to avoid extra vehicle rental cost.