This is an West African tribal cast metal figure known as a goldweight of a woman carrying a child in her arms and a supply jug atop her head. These were produced by the Ashanti, aka Asanti, who are an ethnic group of the Akans in Ghana. These weights evolved from simple geometric forms to figural representations of their culture. These were orginally used as weights for gold dust which was the primary form of currency before coins and paper money. Though it should be inspected in person for dating, this is likely 20th century.
The estimate is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.