If you own a timeshare this is one of those scams to try and rent or sell it for you. They tell you how much it is worth, several thousand dollars more than it's really worth and then ask if you would like to sell it for cash.
The scam is that they advertise it for you, which costs around $600-$800 for the advertisement.
Most time shares are not even worth that much. You can advertise your timeshare on your own for much less money. Try Craigs list or maybe your local newspaper. Again it is a scam, they do not buy it they advertise it!!!!!!!!!!!!