All I can say is it's a good thing I don't live close to a port, I'd be bankrupt booking too many cruises.
I always book when school is in session (no kids) but am unable to book anything during cold months (job).
While trying to go through my bucket list, I also find cheaper getaways in between as my bucket list includes some very pricey destinations.
For me, itineraries, then ship, then cabin costs decide my trip. Inevitably, I must cruise!
Katlady, I would love to have your spreadsheets.