My head is starting to recover from last night's victory celebration. It's always a big party when Brazil and Argentina play the final game of the Libertadores, especially when Brazil wins!
As promised, below are some of the best sites to look for boats in Brazil. Don't expect too much. Prices are in Reais (1USD = 2R$). You'll find that used boats are very expensive here. Argentina has better prices. You might find a foreign-flagged cruising boat for sale in Salvador, Bahia (usually someone who arrives, falls in love with a Brazilian, goes native and decides to stay). Just be aware that foreign-flagged boats can only stay 6 months in Brazil. The only advantage to buying a Brazilian-flagged boat is that you have unlimited time to explore the very long and beautiful coast of Brazil. The current restriction on time is absurd as it is impossible to do much in 6 months on this coast.
Boat brokers and sites in Brazil:
BL3 Escola de Iatismo - Classificados de veleiros
...::: LAY LINE Yacht Broker s:::...
Veleiros usados a venda barcos a vela catamar novos vender veleiro
Veleiro Monocasco e Multicasco em Náutica - MercadoLivre Brasil
In Argentina you could start with the "Mercadolibre" site (like e-bay):
Embarcaciones a Vela en Náutica - MercadoLibre Argentina
If you're serious about buying in Argentina, let me know and I'll track down some better sites for you. Prices in ads are either in USD or Argentine pesos (1USD = 4.2 pesos).