Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Tokyo (91% of total searches to Koshinetsu). The next most popular destinations are Hakuba (5%) and Fujikawaguchiko (4%). Searches for hotels in Nozawa Onsen (1%) are also popular.
KAYAK users have found double rooms in Koshinetsu for as cheap as $41 (Tokyo) in the last 3 days. The average price is $346.