What is Appreciation?
When applied to real-estate, the term "appreciation" means that the property has accrued value over time. Traditional property does generally appreciate over time. However, because timeshares are divided among multiple owners, even if the value of the particular resort itself appreciates, rarely is any net-increase in value apparent to individual owners. Additionally, because the value of a vacation property fluctuates depending on the time of year, it is often difficult to get an accurate appraisal on the resort.
In fact, timeshares most commonly depreciate over time, which is why many owners turn to resale when looking to sell their timeshare. Selling timeshare back to the resort can be costly, as many resorts are only willing to pay the (often arbitrary) amount that the timeshare has been appraised at. With resale, on the other hand, owners can sell their timeshare to interested buyers who will still be saving thousands.
While timeshare resorts are often only willing to buy back the property for a small fraction of your original purchase price, they'll then sell it to buyers at inflated rates based on the market value of the property as a whole. Aside from this already inflated pricing system, resorts must pay for marketing and administrative costs which are often reflected in their timeshare sales price. With resale, buyers are paying only the market value of the timeshare and ultimately save thousands. Resale becomes a win-win for both buyers and sellers!