Fares to Brazil usually go for $600-1200 from the US depending on your departure city. It is unheard of at these rates that tend to be about 40% off!
Some samples that are being tossed around are:
New York-Rio $500
So I thought I would try my hand at it. It seems to be lately that WAS (all Washington DC airports - DCA, IAD, BWI) have had crazy fares. I have seen $380 to Moscow, $400 ...