Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Bangkok (98% of total searches to Central Thailand). The next most popular destinations are Phra Pradaeng (2%) and Ayutthaya (0%). Searches for hotels in Kanchanaburi (0%) are also popular.
KAYAK users have found double rooms in Central Thailand for as cheap as $9 (Bangkok) in the last 3 days. The average price is $75.