Probably. Though I don't have any experience myself, I could see a person owning a page or two of a book someone else is trying to complete, and not selling it simply because they want to keep the pages fro themselves.
Another scenario which I'm sure has happened a few times is when a collector is known to be trying to assemble a book others might go against him to get pages so they can sell it to him at a high price, or as trade bait for something they want that the collector might otherwise not sell.