Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Kanchanaburi (89% of total searches to River Kwai). The next most popular destinations are Sai Yok (10%) and Ban Kaeng Raboet (1%).
KAYAK users have found double rooms in River Kwai for as cheap as £5 (Kanchanaburi) in the last 3 days. The average price is £35.