I think this cruise maybe different, but on the E/bound in 2005, when We were told to book we didn't have any idea of price ranges for the cruise in advance.
So I told DREAMS to go for a lower CAT, to ensure the cost was OK. As soon as I booked I realized my usual CAT 4, was a reasonable price so I asked DREAMS if I could upgrade.
Whilst the ship was sold out in hours, if not a day, I went from an assigned lower CAT room, to a CAT 4 Guarantee, at the same price tier difference as on release, on cheapest pricing.
This time I went straight for a CAT 4,
That is true - if you are already booked and want to change categories you are priced at whatever the tier was for when you first booked it.
This may help you get an idea of what the prices are. Hopefully someone that is booked in a cat 9 that booked it when it first opened can come along and answer the question for you
http://disneycruise.disney.go.com/d...e=15NightEastboundPanamalCanalCruiseRatesPage