obtsining a tour guide fo a day to visit zhujiajiao water town & the price in Shanghai.

For the price, different tour agenice have diffferent price. I happened to join one tour of TravelChinaguide last year, which is called "Water Town Exploration". Although the price is a little bit high, but the service is excellent. I think you may find more information on this website and contact them first to ask for the exact price.
I joined their 10 people group and the fare is around 59U$. Perfect!
BTW, they pick me up at the hotel directly and very easy to take.