Not a lot. Anything beyond a month or so ago is also going to be fairly skewed. I did a quick search and here is your best option on a
buyer maybe as they expressed interest from a different thread.
I used the forum search and it wasn't so bad just have select the box find in title, set max days and only look on the collectibles board.
Personally, just take a photo of one and put it up for an auction without a reserve bid, and a decent min bid increment and 7 days runtime. That's the best way to gauge the market value. That or just post it all with images and ask again, as it will be easier for people to help you when they know what you have.