So it's almost the inverse to the wealth of the country...
SA:
Following a late cash injection from Telkom, along with the main contributions from the Lotto, individual athletes can win R500 000 for a gold medal, R250 000 for silver and R100 000 for bronze at both the Olympics (August 5-21) and Paralympics (September 7-18).
But they have to give 20% to their coach:
http://www.iol.co.za/olympics-rio-2016/teamsa/sa-olympians-can-win-big-money-in-rio-2045405