Disney collects a $95 (I think) trade-in resort fee to cover resort services. People that trade in need to pay it, although they may let you pay upon check-in rather than in advance. For those that trade in, it supposedly helps offset the cost of normal Disney on-site sevices, like resort delivery of items you purchase in the parks, free theme park parking if you drive, etc. These are hidden in the price of "cash reservations" at regular Disney resorts.
We, as
DVC Members also have to pay a $95 fee whenever we trade out of the DVC system. Supposedly it help offset the cost for our Member Services to handle the trade.