Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Queenstown (58% of total searches to South Island). The next most popular destinations are Christchurch (23%) and Lake Tekapo (11%). Searches for hotels in Wanaka (9%) are also popular.
KAYAK users have found double rooms in South Island for as cheap as S$ 24 (Dunedin) in the last 3 days. The average price is S$ 386.