While maintenance fees are based on the calendar year and not the use year, there is a way to determine who should pay fees when not all points are going to be available for the sale.
Disney prorates fees based on how many months are left in the calendar year. You can do the same for a resale contract. In your case, you would only have 1-month of usage of the points during 2006, so you should only reimburse the seller for 1/12th of the 2006 fees they paid in January.
Another way to look at it is this, using a December Use Year. 2005 points are good from Dec 1, 2005 through Nov 30th, 2006. Thus 11/12ths of the 2005 points occur within the 2006 calendar year. So in January of 2006, when the calendar year 2006 fees are paid, you can prorate 11/12ths of the fees as applicable to the 2005 use year points, and 1/12th of the fees applicable to the 2006 use year points.
Suppose the person originally bought the contract Dec 1st 2005. They would have paid only 1-months worth of fees. That being for Dec 2005. In Jan 2006 they pay a full year's fees, so their total now is 13 months worth of fees they have paid. Now, they use ALL their 2005 Use Year points. If they ask you to pay all the fiscal 2006 fees, it would turn out that they got a full use year's worth of points, and only paid 1-month fees, and you would be paying 11/12ths of the fees on those 2005 points that they already used.
Many people seem to think that the fees paid in January are for that year's use year. They are NOT. Do like Disney does for a new purchase, and prorate the fees between buyer and seller based on how many calendar months of the year apply to specific Use Year months.
Hope this helps.