Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Medan (48% of total searches to Sumatra). The next most popular destinations are Pekanbaru (30%) and Bandar Lampung (14%). Searches for hotels in Padang (9%) are also popular.
KAYAK users have found double rooms in Sumatra for as cheap as $9 (Pekanbaru) in the last 3 days. The average price is $48.