Its well known that a timeshare membership is an investment in time with family and NOT in commercial terms.
Here’s a post on http://www.timesharesaleblogs.com that buttresses this point:
The best point made in this article refers to the commitment to family vacations. The value of a timeshare is in the use and creating life-long memories with those you love is priceless. So, when thinking about buying a timeshare don’t try to justify your purchase on an unrealistic expectation of appreciation in value!
Here’s a link to the full article ( Source: http://www.timesharesaleblogs.com )