I don't know that I'd assume that, especially if you haven't booked it yet...or have you, the "quote" throws me off.
I know, in the past, when I've booked a package & the ticket prices increased in August, we had paid for our package in full in July, so we didn't owe anymore...but not sure if you haven't paid in full what would happen?? I want to say there is some verbiage on the documents that say Disney has the right to change the price at anytime?? I could be wrong though, but I would call & ask to find out for sure...