Is there a website for collectors or people trying to determine the rarity of their yoyo for trades that has information like how many runs, versions, pieces, etc of a particular yo-yo there are?
I don’t know of any dedicated collectors’ site, but I can recommend http://yoyowiki.org/
Just check their yo-yo listings.
http://www.yoyomuseum.com/museum_view.php?action=view&subaction=yoyos
That’s a good one for finding price, colors, etc.
This one that’s better for more showing off your throw.