Didn't knew Ayu balls went for so much:
http://page13.auctions.yahoo.co.jp/jp/auction/r42338835
But, they don't even look hand-signed. More like they made a model of her signature on something and then just use spray on the balls and only the signature is left on it.
Oh and I saw this, at first I was like omg and ayu motorcycle for a thousand yen!!!
http://page10.auctions.yahoo.co.jp/jp/auction/m56740953
lol