I've been on all-inclusive resort vacations as well as cruising, and each one has a lot to offer! I'm sure you spend money in others ways while at the all-inclusive. You could tell him how cool it is to be able to unpack only once and visit various ports of call. How about just suggesting a 3-4 day cruise to see if he likes it? Life is too short not to cruise!
Good luck! Let us know what happens....
8/92 Mex. Riv. Commodore
9/98, 9/00, 9/02 & 7/04 Caribbean - Paradise
10/00, 08/05 Pac. Wtrs. Holiday, Monarch
04/06 Hawaii - Celebrity Summit
09/07 Alaska - Celebrity Summit
07/09 Western Caribbean RCCL Liberty of the Seas