Go ahead and tell us what it is, with as much info as you have from the box label or instruction booklet.

This link is the start page to see if there is a "book value" in the RCU Market database.
http://www.rcuniverse.com/product_gu...ubook-home.cfm

Once you have some idea of what to ask for it, this is the starting page to post a free ad
http://www.rcuniverse.com/market/sell-1.cfm