Holding is not a reason not to buy, however you loose the potential for banked, useable points and the value is less. Buying a fully loaded contract with banked points will allow you to start with less points initially and meet your goals or you can keep rolling forward to keep your "bank" full. As Deb & Bill pointed out, the owner cancelled a reservation on short notice, so there is most likely an urgent financial reason to sell...depending on the resort and ROFR trends you might be able to offer a lower, but fair price. I always try to put the shoe on the other foot and think about what I might think is fair in that event so that it is more likely I can at least start a negotiation and hopefully land a good deal.
I commend you for doing your homework and asking the right questions!