Open Science is committed to the widest possible global participation in open access publishing. To determine the appropriate fee, we use a country-based pricing model, which is based on the GNI per capita of the country.
From Mar. 1, 2017 to Apr. 15, 2017, authors can publish papers for free in all journals. When the free event is past, the publication fee can be getting back to normal, authors from different countries are charged differently according to GNI per capita.