The average cost of living in Foz do Iguacu is $681, which is in the top 27% of the least expensive cities in the world, ranked 6804th out of 9294 in our global list and 72nd out of 385 in Brazil.
Yes, Iguazu Falls is a very safe area to visit on the Argentine and Brazilian sides. Although the falls are between Argentina only, the city on the Paraguayan side (Ciudad del Este) is a hectic and is not a safe area to visit. Most of the crimes committed are petty and rarely violent.