It depends on the resort. Some have specific amounts and others the price of a transfer fee (maybe 2,5, or 10x the MF).
We have sold a few on eBay and the people paid the cost of the transfer. We contacted the resort and found that it is not always necessary to involve a closing company. They sent a simple form and we filled it out with the information for the new owner and the resort changed the name on the contract upon receiving the transfer amount.
With 2 of our resales, the people paid us the amount and we hen filled out the transfer papers and sent a check for the amount of the transfer fee and it worked fine. These were resales we had purchased on eBay and used a few years for exchanges and were not looking to get anything out of them. It worked for us.