Being from Ohio, I often fly into Fort Lauderdale for a cruise from Miami. Not only is it cheaper, but I much prefer the Fort Lauderdale airport - much less confusion and congestion than at Miami. There is only a minimal cost difference getting to the port from there. Tri-county airport express has continuous shared ride shuttle service to the Port of Miami for $18 pp and a taxi to the port will run about $60. West Palm is a little further north and ground transportation would be more.