Question : Have you considered flying out of an airport besides Santos Dumont Airport (SDU)?
Answer : Santos Dumont Airport is a superb airport, but in getting you to Atlanta, there is a lower cost option – Galeao Antonio Carlos Jobim International Airport. It's just eight miles away and flights are being priced 27% cheaper over the next few months.
Question : How long do most people visit Atlanta?
Answer : Of course you're not most people, but if you were, you'd stay roughly 15 days.
Question : If your plans are flexible, have you considered changing your departure day?
Answer : The best day to fly on a budget this month is Saturday. Flexibility is paramount when booking travel plans in order to keep travel costs down.