Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Hakone (54% of total searches to Kanagawa Prefecture). The next most popular destinations are Yokohama (39%) and Kawasaki (5%). Searches for hotels in Odawara (1%) are also popular.
KAYAK users have found double rooms in Kanagawa Prefecture for as cheap as $28 (Kawasaki) in the last 3 days. The average price is $220.