I prepaid when I purchased the cruise because I wanted to reserve a certain level room and the Jazz cruises typically sell out. Half of the room options are already sold out -- http://www.davekozcruise.com/#pricing
It is non-refundable because I did not purchase trip insurance - lesson learned.
There was a death in my family 3 months after I purchased, and I am unable to go now due to family obligations.
Please let me know if you have any other questions. As noted above, I am willing to transfer the trip at a discount from what I originally paid.