L.O.
try craigslist.org
it is free- you post your item to sell with your price.. the buyer contacts you by email and if you agree on a price- you meet for the transfer..
we have sold and bought lots of kid stuff on craigslist
I would suggest pricing the item at 1/3 to 1/2 new price.. unless it is brand new in the box- then you may get more for it.