Yeah the Roxas I have is great, and I'm guessing its authentic. As for the sora, I'm almost 100% sure that they all have crown pendants on their necklaces, but I'm not home yet, so when I get home Sunday I will check. If not, I may use the fake KH figures pieces to make a custom Vanitas. That wouldn't be too tough, and I've sculpted for years, so depending on how much time I spend on it, I might be able to do it... Riku's arms would be a nice base for vanitas', but unfortunately I only have one of him, and there's no way I'm breaking him to get his arms. I wish I could find a play arts figure just a bit taller than sora to use as a base though, because I want there to be that obvious physical difference in sora and vanitas except his face.The site is very trustworthy, it's AmiAmi which I researched and is one of the #1 Japan distributors that just recently opened up to international orders.
As for the Play Arts, only counterfeits exist of the first 5 ever released (Sora KH2, Kairi, Roxas, Axel, Sora Final) and then aftewards I guess they thought they weren't profitable enough to make more of (IDK just guessing) so there aren't any other KH counterfeits. Same goes for the Formation Arts (only Volumes 1 and 2 but none afterwards).
There is actually no way to tell if Axel, Roxas, or Kairi are counterfeits. Some of the authentic boxes had stickers on the bottom right advertising the first Chain of Memories manga so if you have that, it's guaranteed authentic, but if not, there's not way to tell so the figures are just as nice.
As for Sora KH2 and Final, his hair will be significantly lighter (closer to a dirty brown if anything) and the key thing is that he will NOT have the crown piece on his necklace. If your figure came with a crown piece but no chain, it's likely the chain broke off but your figure is authentic. However, if your figures has no crown piece, that's nearly a dead giveaway
By the way, on the site it says that everything is in JPY... how do I order it in dollars? Does it do it in the checkout? And also, how bad is shipping?