My pitch to DH for rebooking went like this:
Me:"We need to rebook onboard you know."
DH: "Why? It could be years before we return"
Me: "But if you rebook onboard, you get a discount and on board credit. Think of the
savings"
DH: (insert eye rolling here)
Me: "Savings! Do you hear that word? We could save a lot of money! Plus if we transferred to another
travel agent during their promotion time, we may get an even better deal and that's LESS money out of pocket."
DH: (blink, blink)
Me: "I really think we should. We can always move the dates to a better fit months later. Think about all the money we'll save. If we don't book onboard, we'll lose those credits."
DH:

"You read too much on those boards you visit."
Me:

"Your point is....???"