how do you sell a time share that you are making payments on?

tntsolid says:

You can sell it the day after you bought it if you want to, the catch is that the mortgage is still owed in its’ entirety and you will have to pay it off as soon as you sell the timeshare. If the amount you owe is greater that the amount you are able to sell your timeshare for you will need to come up with the difference to clear the title for the next owner. Good luck on the sale, it is almost impossible to come up with a sale that covers your original purchase price if you bought from a developer.

Timeshares can be sold but the resale value is terrible, if yours is a good one (location, season, size of unit, etc.) then it is easier but it will never sell for half of what you paid for. The average prize that I have seen them been sold is for no more than $2000, and this is for completely paid off timeshares.
There are so many options out there and you are right several owners would just give them away, that it will be almost impossible for you to find someone to take over your payments or give you a good amount for it.
You might want to talk to your accountant about defaulting on the payments.

These are some options:

- Resale is most likely not an option unless you sell it to a friend or relative.
- BE VERY CAREFUL if someone offers to sale it for you and ask for money upfront, they are just a bunch of scammers.
- It is ok to pay a few dollars (no more that $30) to post an ad in some really good site. There are some FREE sites that you can advertise, and my advise is that you just give it away and let someone take over your payments, you can try these:

http://timeshareownerscommunity.com/
http://craigslist.com
http://ebay.com
http://recycler.com/
http://usfreeads.com/
http://www.inetgiant.com/