Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Puerto Iguazú (67% of total searches to Iguaçu National Park). The next most popular destination is Foz do Iguaçu (33%).
KAYAK users have found double rooms in Iguaçu National Park for as cheap as $87 (Foz do Iguaçu) in the last 3 days. The average price is $106.