first, you really would be better to ask on the collectors board, they are very smart and nice over there. That said.
It has been my experience in watching pins sell and buying pins, you are better off to sell most pins individual or at most in small lots. Most people will bid lower on large lots in a per pin price because the total seems higher.
you can sell them on the dis auction board, on the dizpins sale board, ebay or yahoo auctions.
Are you sure you want to sell them all, I enjoy looking at my collection. Get a bullentin board, some stiffened felt from a craft store. Cut the felt to fit in the frame of the board and you can then push you pins in to display them. Just think about why you or if you really don't want them.
You could also try trading on the pinpics website by listing the pins you have to trade and the ones you want.
just some options....hope they help