...hard to tell if it is worth for you - it depends on your names & what you are trying to sell them for - it took me 3 years (2 years with the old afternic and 1 year with the new afternic) before i sold my first and only name , but i just have grappy and overpriced domains...
now seriously , i think its just like any other business , if the right persons finds your listing and it is exactly what he/she/they- is/are looking for and if they have the means to buy it - they will .
there are many places on the internet to sell your domain ,some are better some are worse - i personally think afternic is one of the better (because of their great support).
some places are cheaper to sell your domain and some are a little more expensive , so it depends on your wallet.
i think the more places you offer your domain ,the better ,the greater the changes to sell your domain...if the right person...blabla...