You may want to post this on the collectors board. There are certain pins that you need to watch out for as being non-tradeable. Again, the folks on the collectors board can steer you in the right direction.
Chuck65 is correct. You can get lots of help on the Collectors Board and there is LOTS of info on Pinpics.com. Enjoy and remember...it's highly addictive.
I have browsed some of those sites, and they seem to be legitimate. I've heard of ebay working out for some people, but I'd look at the collector's board and look at the other websites first.