You have no obligation to pay the dues. It's all in what you negotiate when you make the offer on the resale. I've even seen a few offers described as "net" offers. These were ones where the potential buyer said "my offer is that I will write a check for $xxxx in exchange for your contract. That $xxxx is all that I will pay and includes any closing fees, required legal fees, next day document delivery fees, dues, etc. You, Mr. Reseller, figure out what the seller would net from my offer and determine if he will accept it."
Resale conditions and motivation vary. Sometimes the sale is from an estate, or because of a divorce, and the seller is really motivated. It's just like buying a house - virtually everything in the deal is negotiable.
Cap