$600 price difference.
Remember the rates may reflect different sailing weeks as well as categories of available cabins. Another thing the has an effect on the cruise prices is are the port charges leveed by each port - the cruise lines can not change these.
A Bad Day At Sea [with power] Always Beats A Good Day At Work
Alaska 2014 - haven't picked a cruise yet
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, Caribbean 2013