I'm a big advocate for Disney cruises. Once you've done one, there will be no turning back.
Karen - I'd never been on anything larger than the Manly ferry until we went on a 7-night cruise on the Disney Fantasy. Della and I were paranoid about sea sickness, but in the end - we had no ill effects at all and had a wonderful time. We then did the Alaska/Hawaii cruises back to back on the Disney Wonder and were expecting the worse for the Hawaii cruise across the Pacific and still we had a wonderful time with no ill effects. On that back-to-back cruise, we spent 17 nights on board and it still wasn't enough to do everything!!! In fact, the port days were getting in the way of us doing the fun ship stuff LOL.
But you're right, they aren't cheap - so I get it if house repairs are a priority! But don't let the motion put you off doing a future cruise - and if motion is a problem, try the Alaskan cruise someday - it goes up the inside passage so you aren't even in open waters for most of the trip, but smooth sheltered water.
DLR: 2005, 2006, 2009, 2011, 2012, 2013, 2015
HKDL: 2006 (Mar & Sept), 2011 (Apr & Dec), 2014
TDR: 2008, 2010, 2017
WDW: 2006, 2013 (Mar & Sept), 2016
DCL: 2013, 2015 (Alaska & Hawaii)