dkis4nu, we tried to upgrade at the port from a Cat 8 to a Cat 6 or 5, but the ship was sold out (12/20/03). My DH had been talking to some neighbors who had been on the Magic over Thanksgiving in a Cat 5 and just went on and on about how much they loved their verandah. Unfortunately, he does not frequent the boards, and never mentioned this to me until the day before we sailed, when we were already at WDW, and trying to get all the last minute errands (mailing Xmas gifts, going to the bank, etc.) done before we boarded.
We were more than willing to pay the price...which I believe would have been the highest price for the cabin, if the "closer to the date of sail, the higher the price" theory still prevails the date of sailing. I know that in checking prices for various sailings, the more expensive cats always seem to sell out first, or as the date draws near, Disney is upgrading the lower cat reservations to release lower priced cabins for sale, as those are more marketable and they are able to fill up the ship.
I subscribe to a number of Cruise company websites, and never, ever, have I seen a
Disney cruise on a "last minute, cheap price" type list.
You might be able to figure out what your difference would be by going to the
DCL website and seeing what the price is for a Cat 9 for the next two sailings for your itinerary. You are only four weeks away, and for this time of year, I would be surprised if there was a tremendous increase in price.
You might check with your TA, or even DU to see if they have any suggestions about trying to get this accomplished beforehand. We decided in August, 2003 (after the ship was sold out) to sail on the 12/20 sailing, but I couldn't find a cabin for sale anywhere. I finally found a TA that had bought up a large number of cabins when the 12/03 dates were released, and they still had 6 or 7 left. It was hard for me to tell whether I got a decent price because the prices were not posted on the DCL site, as everything was sold. We took the best available, which was a Cat 8, for the four of us.
When we got to the port, I had hopes of cancellations enabling us to upgrade, but I guess that would have been more prudent to check on Day 59!
I do have a very good friend who is on these boards a lot (he carries a big fish), whose mantra goes something like this: "Book the cheapest cabin on the best ship -- all you do is sleep there."
I may take his advice next time!
Good luck - have a great trip and let us know if you managed to get upgraded!