For average cost, you should enquiry a travel agent. You can try this TravelChinaGuide. My friend used it. I have been to Xitang, I think others are similar, for they are all water towns. If you do not travel in weekends and public holidays, no problem to stay in the village's inns, hotels without booking in advance. Accomodation is cheaper too. Another suggest is waters towns look similar in this area. Those towns you mentioned are not far from each other. I will be not interested in so many similar scenes at one time. If you are interested in old towns, Fenghuang Town in Hunan, Wuyuan in jiangxi, Xidi and Hongcun Village in Huangshan are all famous ones.