We just booked our airfare on Travelocity. American Airlines SFO to Miami, Miami to Rio, return from Santiago Chile, through Miami to SFO. Fare per person was $1,200, more than $500 per person less than Celebrity wanted for aifare, with no guarantee of airline or schedule.
We booked our January 6, 2002 sailing (Rio to Valparaiso) in April, and paid $1,500 per person for a cataegory 4 cabin (that's one category below veranda cabins) I think it's a steal for two weeks in South America.
Look around for air fares. There are lots of good deals out there.