We inquired about doing a back-to-back cruise on the Dawn (14 days, different iineraries) sailing December 2, 2000 from San Juan. The only discount they were willing to offer was a waiver of the port charges for the second half; a savings of roughly $80/person.
Not exactly the discount we had expected, especially since we are Captain's Circle members and three-time (would've been four) Princess cruisers.
Needless to say, we passed on the "deal".
For other reasons, we're on Celebrity Galaxy out of San Juan on 12/2/2000 with four days pre-cruise and one day post-cruise in San Juan.