It's a good site.  I've picked up a bunch of great stuff from there.  Great place for Thomas the Tank Engine Stuff.  Picked up a complete Clickety-clack track Bridge and Tunnel set for an awesome price a couple of years ago. 

The only thing you have to watch there is that most of the Goodwills have a handling fee that's disclosed in the disjointed text layout, but still easy to miss.  The shipping is often on the high side, as well, and you have to use the calculator link to see it.  Definitely deals to be had, but you just have to factor those things in.