I'd say the "government fees and taxes" seem never to be included in cruise prices. True, the cruise line does not control this and they may change, but they are pretty well known and in the internet age the changes could be disseminated quickly.
Just like baggage fees experienced travelers know these fees are coming your way, but they can still be a surprise.
All I ask is a tall ship and a star to steer her by; John Masefield
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014, Regal 2014, 2016
Star Clippers: Royal Clipper 2015