I not sure money is a BIG issue but I think he would rather have money to spend on the cruise than use it on the hotel. It is just for the night before the cruise and just a place to sleep I think. Somewhere near the cruise terminal (or at least not on the other side of town) would be preferable.
They are not driving in, do you know of any that offer a cruise shuttle?
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013