Recently came to know of following two places which buy kids stuff (new/used). One needs to take appointment in advanced.
Kid to Kid
The Kidz Shoppe
Also for any kind of books – Half Price Book Store
I have not used any of the above listed services but plan to use them sometime soon.
http://www.playitagainsports.com/
I finally made a trip to Kid To Kid and i would rate it ok not excellent – its a good place for a one stop shop i.e you don’t have to upload it on craigslist or manage individual buyers if you have lot of stuff. The owner took lot of time in analyzing each item that i took. The return that they pay is very less (1/3rd of the value @ which their software suggests selling price) + they will only accept items that they think they will be able to sell. I’ve also heard from another friend that they did not take any item she took for selling, whereas Sejal mentioned that they took all of the stuff she wanted to sell. They also sell new stuff (limited though). And most of the stuff that they buy/sell is baby/toddler appropriate.