How do i go about selling a timeshare?

I have come across 2 ways. One way, asks for $500 up front for "ad" fees to post it on their web site. ( I am not entirely trusting of this), I have also seen sites for timeshare brokers who get commission after its sold. Which may be costly also. Which is the best? I'm not really trying to make any money off of it and I already know I may get far less than what I paid for it and to a point.. that is fine. I just dont want to keep paying for it in the future. HELP!!! ....and if you have any horror stories I would love to hear them, at least I know the worst I'm in for. Thanks

Ps. I have a deeded timeshare, where I'll own it after (seemingly) a trillion payments. (boy... what were WE thinking)