As we have discovered with our forthcoming cruise on the Diamond,the price attached to the original offer may not be reduced,but subsequent offers re the same cruise may be more attractive.
It is true that by booking late one will not receive the category/location of one's choice,but given the high quality of the entry level suites on the luxury Lines one is not exactly slumming it!
Perhaps we have been lucky,but twice,on our guarantee basis,we have been upgraded by as much as three categories.